EP0564018B1 - Device and method for regulating the tension of a filamentary material, especially of a winding wire for electric coils - Google Patents

Description

The invention relates to a device for regulating the tension of a thread-like material guided from a supply roll to a spool of a winding device with the features specified in the preamble of claim 1 and a method for controlling such a device.

The tensioning forces for the winding wire in a winding system for electrical coils are to be kept constant in a predetermined value by an automatic wire tension regulator being arranged between a wire supply roll and the coil winding device. The requirements for such a wire tension controller are diverse because the wire tension can fluctuate greatly during the winding process due to the coil shape, and the coil shape is round, square, rectangular, oval and the like. can be formed and is influenced by the growing diameter of the winding during winding. It must be taken into account that the wire speed, for example in the case of technologically related process sequences, can also assume negative values. The fast effectiveness of the wire tension controller is particularly important, because delays due to inertia bring uncontrollable wire-tension ratios, which can severely affect the quality of the finished winding.

In conventional wire tension regulators, the voltage is regulated, for example, by mechanical and / or electromechanical means, preferably by a wire compensation arm, optionally with a potentiometer assigned to it.

Devices of this type have major disadvantages caused by inertia, in particular due to running or braking of the wire during a currently occurring negative wire speed and undesirable vibrations of the wire compensation arm.

From DE-OS 40 35 862 a device for voltage regulation of a wire for winding an electrical coil is known, which provides an improvement through an automatic regulation of the wire tension and its braking. The device consists of a pre-brake, which is formed from two rollers covered with felt, one of which is permanently driven in the opposite direction to the direction of travel of the wire by a synchronous motor and the other is carried along as a pressure roller by the driven roller. The pre-tensioned wire is guided through a grooved roller through at least 360 °, which is driven by a further motor in the wire run and wire return directions. The grooved roller is connected to a tachometer, which emits a signal, whereby the motor is controlled by a controller. A strain gauge provides a signal representative of the wire tension, which is compared to a target value. The resulting signal is superimposed on the signal from the tachometer in order to influence the controller via a control signal. The change in wire tension affects the signal and the speed of the motor changes. to suppress this change in voltage. At higher take-up speeds, the quality of the wound coil at high wire speeds is impaired by voltage differences. In order to counteract the delays caused by inertia, the winding wire is guided over a spring-loaded swivel arm. The winding wire then runs over a roller which is provided with a code disk in order to bring about corresponding corrections of the strain gauge signal via an additional control device. A disadvantage, which affects in particular in multiple winding machines, is that the spring force of the swivel arm must be individually adapted for each winding point for each winding process influenced by the wire type and wire thickness. Such a voltage regulation is less suitable for particularly thin winding wires which are wound at high take-off speeds and in which only the frictional force alone is decisive.

Furthermore, from DE 40 35 862 A1 a wire tension control device is known, in which the wire voltage is measured here with the aid of a strain gauge, which provides an actual wire voltage signal which is compared with a predetermined setpoint wire voltage signal with the aid of a comparator, the output signal of which is then used the regulation of the wire tension is used.

The invention has for its object to provide a device for voltage regulation, in particular of thin winding wires, which are wound at high tightening speeds, without the need for compensation elements such as wire compensation lever, code disk and a pre-brake with felt clamps, each with additional non-programmable setting elements by hand must be compared, are required. Furthermore, the invention is intended to provide a method for controlling such a device.

This object is achieved by a device or a method having the features specified in claim 1 or claim 13, further developments of the invention being characterized in the subclaims.

One advantage is the torque control of the - brushless - DC motor by means of a digital current control circuit, through which the speeds of the brake wheel are derived in an advantageous manner.

The fact that the actual values of the amplified rotor position signals provide a feedforward control of wire speed and wire acceleration, in which the actual values for these functions are derived from the commutation system, which is a part of the DC motor, are no additional devices for correcting the winding wires that are thin at high wire speeds Voltage differences required.

Since no mechanical compensation devices are necessary for the wire voltage fluctuations that occur, the setpoint wire tension control can also be changed without interruption during the winding process.

The digital parameter specification and digital control loops ensure precise reproducibility of the winding process.

Another advantage is that all the necessary control and regulating elements, including the power supply units, are integrated in the wire-pull regulator, so that additional control units are also unnecessary.

The fact that the wire breakage can be detected and displayed immediately thanks to the accelerated wire retraction means that all other necessary devices are no longer required. No additional devices are required to determine the wire length for each wound coil.

By using a two-wire line (bus system), several, for example up to 32 wire tension controllers can be connected to a common machine control of the winding device, which can be individually programmed, with additional statistical and operating data being recorded and registered.

In the drawing, an embodiment of the subject of the invention is shown schematically.

• Fig.1 eine perspektivisch dargestellte erfindungsgemässe Vorrichtung,
• Fig.2 eine Prinzipskizze der Vorrichtung gemäss Fig.1,
• Fig.2A ein schematisch dargestellter Anschluss für mehrere Drahtzugregler an eine Maschinensteuerung gemäss Fig.2, und
• Fig.3 ein Funktionsschema eines Steuergerätes gemäss Fig.2.

It shows

• 1 shows a device according to the invention shown in perspective,
• 2 shows a schematic diagram of the device according to FIG. 1,
• 2A shows a schematically illustrated connection for a plurality of wire tension regulators to a machine control according to FIG. 2, and
• 3 shows a functional diagram of a control device according to FIG. 2.

Identical parts are provided with the same reference symbols in all figures.

According to FIGS. 1 and 2, a thread-like material, such as aluminum, copper, tungsten, gold and platinum winding wires, but also plastic and glass fibers, preferably in the form of continuous fibers, is hereinafter referred to as a winding wire 25 , out of a supply spool (not shown) in the direction of the arrow of a device designed as a wire voltage regulator 10-1 between a retraction roller 16 driven by a DC motor 14 by means of a transmission 15 in the wire return direction and a pressure roller 17 which can be pressed on by means of a spring 19. The pressure roller 17 carried by the retraction roller 16 can be pivoted out or delivered relative to it. Depending on the type of wire and wire thickness, the retraction roller 16 and / or the pressure roller 17 is provided with correspondingly suitable coverings, for example made of felt, ceramic, metal, rubber, vulcanized rubber and / or an antistatic material, with smooth winding wire made of antistatic material for thin winding wires existing toppings are preferred. The contact pressure of the pressure roller 17 can be adjusted by adjusting the spring length 19 depending on the type of wire and -thickness can be changed. The revolutions of the retraction roller 17 vary in accordance with the wire speed. The winding wire is subsequently wrapped 360 ° in its groove via a brake wheel 22, the brake wheel being controlled by a brushless DC motor 20 with incremental encoder 21 in four-quadrants and in wire run or wire return. Direction is driven. The brake wheel 22 is also provided with a flexible covering, preferably made of rubber, Vulkolan or the like, so that these measures ensure a non-slip wire guide in the wire run and wire return directions.

The applied voltage of the winding wire 25 is subsequently continuously determined by a pathless force measuring device, preferably a stretch mark 30, in that the winding wire 25 does not lead to a measuring roller 32 and the stretch mark 30 and at a constant angle around a wire deflection 34, for example an eyelet or swab tail shown coil of a winding device is pulled.

For better threading of the winding wire 25 between the retraction roller 16 and the pressure roller 17, a wire deflection 26 and a further wire deflection 27 are provided in the area below the brake wheel 22. An on / off switch 12 and a light indicator 13 "green / red (fault)" are also arranged on the front side of the wire-pull regulator housing 11.

The DC motor 20 is brushless and regulated in four quadrants, so that a long service life is guaranteed even at very high wire speeds of approximately 30 m / s. From a DC motor 20 to a motor controller 28 emitted rotor position signal S1, an amplified rotor position signal S2 is supplied to a control unit 40 in the motor controller 28 and, on the other hand, an actual value torque signal S3 derived from an energy supply E supplied to the direct current motor 20 likewise influences the control unit 40 by means of a digital current control loop 20, S1.28, S3.40.

In addition, either a setpoint wire voltage signal S6 programmed in a machine controller 50 or, if no setpoint programming S6 is provided, a setpoint entered in a wire voltage preselection 52 is transmitted to the control unit 40 as a wire voltage signal S6 '.

The setpoint wire voltage signal S6 or S6 'is compared with a signal S5 amplified in an amplifier 38 with the instantaneous wire voltage 30, S4, 38, S5, 40 in the control unit 40, corrected if necessary (FIG. 3) as a manipulated variable. Signal S7 to the motor controller 28 and in this amplified output as energy supply E to the direct current motor 20 in order to convert the voltage of the wire 25 from its current actual value to the desired value. The digital wire tension control is superimposed on the torque control, with the DC motor 20 forming a closed control circuit 30, S4, 38, S5, 40, S7, 28, E, 20 with the pathless force measuring device 30, preferably the strain gauge. The strain gauge 30 prevents the tendency of the winding wire to oscillate, for example in the case of mechanical wire tension compensation elements.

As soon as the wire friction force reaches the setpoint wire tension S6 or S6 'of the machine control 50 or the wire tension preselection Exceeds 52, the braking function of the DC motor 20 changes into a drive function, which can occur in particular with a thin winding wire 25 running at high wire speed.

The actual values of the wire speed K1 and the wire acceleration K2 are derived in the control unit 40, as will be described in more detail in FIG. 3, from the amplified rotor position signal S2 from the commutation system, which is the direct current motor 20, whereby the rotational speeds of the direct current motor 20 and an incremental encoder 21 is arranged on the DC motor axis for measuring the wire length.

In the case of secondary winding operations, such as when the wire guide is displaced or when the winding spindles are rotated backwards, such a technologically induced wire retraction can be programmed by an existing or existing wire retraction force in the machine control 50 or in the wire tension preselection 52. A wire tightening is brought about by the wire retraction, the wire length of the wire retraction being likewise programmable in the machine control 50.

A broken wire detection, which is derived from the retraction function and the wire acceleration, is indicated as a fault by means of the illuminated display 13.

As a rule, the winding machine for electrical coils has several, for example up to 32 winding stations, which are equipped with corresponding individually programmable wire tension regulators 10-1 ... 10-32 (Fig. 2A). With a two-wire line, a so-called bus system, the wire tension controllers 10-1 ... 10-32 are connected to the machine control 50 connected, in addition to the setpoint programming, actual value transmission, tolerance range programming, for example in the case of wire stretching with alarm triggering, wire pull controller programming. In addition, 50 statistical and operating data are recorded and possibly registered in the machine control, such as min / max wire pull per coil and motor and strain gauge operating data.

A digital parameter specification and digital control loops result in perfect reproducibility for a wide variety of winding processes.

In the control device 40 according to FIG. 3, the amplified rotor position signal S2 emitted by the motor controller 28 is fed to a counter C1, the counter reading of which derives correction signals K1, K2 for wire speed and wire acceleration. The setpoint wire voltage signal S6 or S6 'is compared with the digitized in an analog / digital converter AD2, with the amplified actual value wire voltage signal S5 supplied by strain gauges 30 in a comparator V1, and the difference signal S8 with a wire tension controller R1 supplied, the output signal S9 is corrected by the correction signals K1, K2. This corrected signal S10 is compared with the actual-value torque signal S3 digitized in a further analog / digital converter AD1 in a corresponding comparator V2 and the resulting signal S11 is transferred to a torque controller R2, whose output signal S12 transmits it processes a pulse width modular PWM (pulse wide modular) into a manipulated variable signal S7. As already described, the manipulated variable signal S7 is amplified in the motor control 28 and supplied to the direct current motor 20 as an energy supply E.

Claims (15)

1. Device for regulating the tension of a filamentary product, preferably a winding wire (25) guided from a supply roll to a coil of a winding device, in particular for electrical coils, consisting of

   - a pull-back roll (16) with a pressure roll (17), as well as a brake wheel (22) which is driven in the forward and reverse directions of travel of the wire by a controlled direct current motor (20),

   - a pathless force measuring device, preferably in the form of a strain gauge (30) for supplying an actual-value wire tension signal (S5), arranged between the brake wheel (22) and the winding device,

   - and a comparator (V1) which compares the amplified actual-value wire tension signal (S5) with a setpoint wire tension signal (S6, S6') and delivers a control signal (S8) for the direct current motor (20),

   characterised in that

   the controlled direct current motor (20) outputs a signal (S1) of the rotor position to a motor controller (28) which it passes as an amplified signal (S2) on the one hand to a control unit (40), to which, furthermore, is fed an actual-value torque signal (S3) and a setpoint wire tension signal (S6) of the machine controller (50) or a setpoint wire tension signal (S6') of the wire tension preselection (52),

   and that in the control unit (40) the control signal (S8) passes to a wire tension regulator (R1) whose output signal (S9), together with an actual-value torque signal (S3), is fed to a torque regulator (R2) to derive a manipulated variable signal (S7) that is output to the motor controller (28) and is amplified by said motor controller (28) as an energy feed (E) to the direct current motor (20) to regulate the wire tension to the setpoint value.
2. Device according to Claim 1, characterised in that the controlled direct current motor (20) is brushless and has four-quadrant regulation.
3. Device according to Claim 1 or 2, characterised in that a digital current control loop (20, S1, 28 S3, 40) is provided for torque control of the direct current motor (20).
4. Device according to one of Claims 1 to 3, characterised in that the digital wire tension control is superimposed on the torque control, the direct current motor (20) with the pathless force measuring device (30) being a closed control loop (30, S4, 38, S5, 40, S7, 28, E, 20).
5. Device according to one of Claims 1 to 4, characterised in that the commutation system of the brushless direct current motor (20) is provided for the actual values of the wire speed (Kl) and wire acceleration (K2).
6. Device according to one of Claims 1 to 5, characterised in that an incremental encoder (21) is disposed at the spindle of the direct current motor for measuring the speeds of the direct current motor (20) and for measuring the length of wire.
7. Device according to one of Claims 1 to 6, characterised in that where the frictional force of the wire is higher compared to the setpoint wire tension (S6) of the machine controller (50) or the setpoint wire tension (S6') of the wire tension preselection (52), respectively, the braking function of the direct current motor (20) is a drive function.
8. Device according to one of Claims 1 to 7, characterised in that a technologically-dependent wire pull-back can be programmed by a controlled wire pull-back force in the machine controller (50) or wire tension preselection (52), respectively.
9. Device according to one of Claims 1 to 8, characterised in that programming is provided for the determination of the wire length of the wire pull-back in the machine controller (50).
10. Device according to one of Claims 1 to 9, characterised in that programming is provided for the determination of the wire length of the wire pull-back in the machine controller (50).
11. Device according to one of Claims 1 to 10, characterised in that a wire break can be detected during a wire pull-back with predetermined minimum wire acceleration, and a visual indication (13) is provided for this purpose.
12. Device according to one of Claims 1 to 11, characterised in that the coatings for the pull-back roll (16), the pressure roll (17) and/or the brake wheel (22) consist of felt, plastic, ceramic, metal, rubber, vulcolan and/or antistatic material, according to the type of wire and wire gauge.
13. Process for controlling the device having the features stated in one of Claims 1 to 12, characterised in that in the control unit (40) the amplified rotor position signal (S2) is fed to a counter (C1), from whose counter reading correction signals (K1, K2) for wire speed (K1) and wire acceleration (K2) are derived, that the setpoint wire tension signal (S6 or S6', respectively) is compared (VI) to the digitized (AD2), amplified actual-value wire tension signal (S5) delivered by the force measuring device (30), and the difference signal (S8) is fed to the wire tension regulator (Rl), whose output signal (S9) is corrected by the correction signals (K1, K2), that this corrected signal (S10) is compared (V2) with the digitized (AD1), actual-value torque signal (S3), and the resulting signal (S1) is fed to the torque regulator (R2), whose output signal (S12) is processed into the manipulated variable signal (S7) via a pulse-width modulator (PWM).
14. Process according to Claim 13, characterised in that in the motor controller (28), the actual-value torque signal (S3) is derived from the energy (E) supplied to the direct current motor (20).
15. Process according to Claim 13 or 14, characterised in that the wire length for the wound coil is measured by an incremental encoder (21) of the direct current motor (20) and via the amplified rotor position signal (52) fed to the control unit (40) and to the counter (C1).

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