EP0564018A2 - Device and method for regulating the tension of a filamentary material, especially of a winding wire for electric coils - Google Patents

Abstract

In order to regulate the wire tension on a winding device for electrical coils, a wire tension regulator (10-1) is arranged, in the case of which a withdraw roller (16) and a contact-pressure roller (17), which can be pressed against said withdraw roller (16), are provided for initial braking of the winding wire (25). The winding wire (25) is subsequently looped through 360 DEG over a braking wheel (22), it being possible to drive the braking wheel (22) in the forward and reverse directions of the wire by means of a DC motor (20), and a strain gauge (30) being arranged between the braking wheel (22) and the winding device. The DC motor (20) emits a rotor-position signal (S1) to a motor controller (28) which on the one hand passes said signal on as an amplified signal (S2) to a control unit (40) and, on the other hand, passes a derived actual-value torque signal (S3) to the control unit (40) as well. In addition, a desired-value wire tension signal (S6) is passed from the machine controller (50) to the control unit (40), and a desired-value wire tension signal (S6') is supplied from the wire tension preselector (52) to the control unit (40), and the desired value (S6 or S6') of the wire tension is compared with a signal (S5) representing the instantaneous wire tension (30, S4, 38, S5, 40), the control unit (40) emitting a control variable signal (S7) to the motor controller (28) and, amplified via said controller, as a power supply (E) to the DC motor (20), in order to change the tension of the wire (25) from its present value to the desired value. <IMAGE>

Description

The invention relates to a device and a method for regulating the wire tension on a coil winding device according to the preamble of claims 1 and 13.

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, since the wire tension can fluctuate greatly during the winding process due to the coil shape, the coil shape being 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 a running or braking of the wire during a currently occurring negative wire speed and due to undesired vibrations of the wire compensation arm.

According to DE-OS 40 35 862, a device for regulating the tension of a wire for winding an electrical coil is known, which provides for an improvement by automatically regulating the wire tension and braking it. The device consists of a pre-brake, which is formed on 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 set point. 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 voltage change. At higher take-up speeds, the quality of the wound coil at high wire speeds is impaired by voltage differences that occur. 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 appropriate corrections of the strain gauge signal via an additional control device. A disadvantage, which has an effect particularly in the case of 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 for which only the frictional force is decisive.

Starting from this prior art, it is an object of the invention to develop a wire tension controller and a method, in particular for thin winding wires that are wound at high tightening speeds, in which compensation elements, such as wire compensation levers, code disk and a pre-brake with felt clamps, each with additional there is no need for non-programmable setting elements that have to be adjusted by hand.

The above object is achieved by the characterizing features of claims 1 and 13. Further designs of the device and method steps are specified in dependent claims.

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 owned by 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 required 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, and additional statistical and operating data can be 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 filamentary 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 referred to below as a winding wire 25 , from 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 direct current 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, Vulkolan and / or of an antistatic material, with thin winding wires being made of antistatic material existing toppings are preferred. The 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 according to the wire speed. The winding wire is subsequently wrapped 360 ° in its groove by means of a brake wheel 22, the brake wheel being controlled by a brushless DC motor 20 with incremental encoder 21 in four-quadrants, 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 stretching strip 30, in that the winding wire 25 does not lead to a measuring roller 32 and the stretching strip 30 and at a constant angle around a wire deflection 34, for example an eyelet or swaging 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 DC motor 20 in order to convert the voltage of the wire 25 from its current actual value to the setpoint. The digital wire tension control is superimposed on the torque control, with the DC motor 20 forming a closed control loop 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 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 in the case of a thin winding wire 25 running at a 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, for example, when the wire guide is moved or when the winding spindles are rotated backwards or the like, such a technologically induced wire retraction can be programmed by an existing or existing wire retraction force in the machine controller 50 or in the wire voltage preselection 52. A wire tightening is brought about by the wire retraction, the wire length of the wire retraction also being programmable in the machine control 50.

A broken wire detection, which is derived from the retraction function and the wire acceleration, is displayed 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 positions, 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, whereby in addition to the setpoint programming, actual value transmission, tolerance range programming, for example in the case of wire stretching with alarm triggering, wire tension controller programming can be carried out. 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 nominal value 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 is compared to a wire pull -Regulator 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 transmitted 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 controller 28 and supplied to the direct current motor 20 as an energy supply E.

Claims (15)

Device for regulating the tension of a thread-like material, preferably a winding wire (25), which is guided from a supply roll to a coil of a winding device, in particular for electrical coils, consisting of a retraction roller (16) with a pressure roller (17) and a brake wheel (22), which is driven in the wire run and wire return directions by means of a regulated direct current motor (20) and a pathless force measuring device, preferably a strain gauge (30), is arranged between the brake wheel (22) and the winding device, characterized in that the regulated direct current motor (20) emits a signal ( S1) of the rotor position to a motor controller (28) which, on the one hand, transmits it to a control unit (40) as an amplified signal (S2) and, on the other hand, a derived actual value torque signal (S3) also reaches the control unit (40), which also a setpoint wire voltage signal (S6) of the machine control (50) or a Setpoint wire voltage signal (S6 ') of the wire voltage preselection (52) is supplied and the setpoint (S6 or S6') of the wire voltage with an amplified signal (S5) of the instantaneous wire voltage (30, S4,38, S5,40 ) is compared and the control unit (40) outputs a manipulated variable signal (S7) to the motor controller (28) and, via this, amplified as energy supply (E) to the direct current motor (20) in order to reduce the voltage of the wire (25) from its current one Transfer the value to the setpoint. Apparatus according to claim 1, characterized in that the regulated DC motor (20) is brushless and has a four-quadrant control. Apparatus according to claim 1 or 2, characterized in that a digital current control circuit (20, S1, 28, S3, 40) is provided for torque control of the direct current motor (20). Device according to one of claims 1 to 3, characterized in that the digital wire tension control is superimposed on the torque control, the DC motor (20) with the pathless force measuring device (30) being a closed control loop (30, S4,38, S5,40, S7, 28, E, 20). Device according to one of claims 1 to 4, characterized in that the commutation system of the brushless DC motor (20) is provided for the actual values of the wire speed (K1) and the wire acceleration (K2). Device according to one of claims 1 to 5, characterized in that an incremental encoder (21) is arranged on the DC motor axis for measuring the rotational speeds of the DC motor (20) and for measuring the wire length. Device according to one of claims 1 to 6, characterized in that when the wire friction force is higher than the setpoint wire tension (S6) of the machine control (50) or the setpoint wire tension (S6 ') of the wire tension preselection (52) DC motor (20) is a drive function. Device according to one of claims 1 to 7, characterized in that a technologically induced wire retraction by a controlled wire retraction force in the machine control (50) or wire voltage preselection (52) is programmable. Device according to one of claims 1 to 8, characterized in that programming is provided in the machine control (50) for determining the wire length of the wire retraction. Device according to one of claims 1 to 9, characterized in that when a wire is withdrawn with a predetermined minimum wire acceleration for a wire break, a light indicator (13) is provided. Device according to one of claims 1 to 10, characterized in that the revolutions of the retraction roller (16) is variable according to the type of wire and the wire thickness. Device according to one of claims 1 to 11, characterized in that the linings for the retraction roller (16), the pressure roller (17) and / or the brake wheel (22) according to the type of wire and the wire thickness made of felt, plastic, ceramic, metal, Rubber, Vulkolan and / or electrically antistatic material exist. Method for controlling the device according to one of claims 1 to 12, characterized in that in the control unit (40) the amplified rotor position signal (S2) is fed to a counter (C1), from whose count correction signals (K1, K2) for Wire speed (K1) and wire acceleration (K2) are derived from that the setpoint wire voltage signal (S6 or S6 ') with the digitized (AD2) with which the actual value wire voltage signal (S5) supplied by the force measuring device (30) is compared (V1) and the difference signal ( S8) is fed to a wire tension controller (R1) whose output signal (S9) is corrected by the correction signals (K1, K2), that this corrected signal (S10) with the digitized (AD1) actual value torque signal (S3 ) is compared (V2), and the resulting signal (S11) is fed to a torque controller (R2), the output signal (S12) of which is processed via a pulse width modulator (PWM) to the manipulated variable signal (S7). Method according to claim 13, characterized 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). A method according to claim 13 or 14, characterized in that the wire length for the wound coil from an incremental encoder (21) of the DC motor (20) and via the amplified rotor position signal (S2) supplied to the control unit (40) and the counter (C1) is measured.

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