WO2009045180A1

WO2009045180A1 - Improved system for producing enamelled copper wire windings fnr electrical equipment

Info

Publication number: WO2009045180A1
Application number: PCT/SM2008/000007
Authority: WO
Inventors: Pier Paolo Comellato
Original assignee: ICEM SpA
Current assignee: ICEM SpA
Priority date: 2007-10-02
Filing date: 2008-09-19
Publication date: 2009-04-09
Anticipated expiration: 2010-04-02
Also published as: SM200700039A; SM200700039B

Abstract

A system (100; 200) for producing enamelled copper wire windings for electrical equipment comprises the steps of: setting data identifying significant characteristics of the wire; preliminary measurement of significant characteristics of the wire and allocation of said data and measurements taken to a suitable storage archive; feeding a winding section, equipped with at least one rotary spindle, with a continuous copper wire that has a circular cross-section; measuring the significant characteristics of the wire at least regarding their part susceptible to modification during the production process; comparing at least said characteristics with the data held in the storage archive, identifying any deviations; according to said deviations, identifying operating parameters for the winding section; managing the winding section based on the operating parameters saved.

Description

Improved system fnr producing enamelled copper wire windings for electrical equipment

Technical Field

The present invention relates to the production of electrical equipment which uses windings made of enamelled copper wire with a circular cross-section, and more particularly it relates to a system for producing the windings, improved to allow the achievement of the highest product quality.

Rackgroπnd Art

Companies which produce wires for electrical windings use, as guidelines, various product standards for the production and testing of copper wire. Said regulations include data regarding the various characteristic elements of the wire, indicating the relative tolerances, that is to say, indicating minimum or maximum deviations allowed relative to the nominal reference values. hi contrast, in the construction of electrical equipment which uses the wire as a starting semi-finished product for making windings, it is the electrical equipment designer who identifies at the equipment study/calculation step the characteristic data of the wire according to the regulations, the size of the equipment, the use for which it is intended, for example continuous or intermittent service, the future positioning in particular zones, for example subject to the risk of explosions, the product end market, which may influence its characteristics, etc. During the next step of making the product, the design data is checked, including that relating to operation and life required, to arrive at definitive product validation.

Any changes to the design data are then made : based on the production results, based on specific requests, or based on indications supplied by the quality control.

However, the process for actually making the product is affected by a large number of variables which may cause even significant deviations in the characteristics of the wire used to form the winding. This is easier to understand by referring, for example, to the production of a high voltage stray flux transformer, more commonly known as a neon transformer, specific for switching on discharge lamps, for lighting.

Such a transformer has an active part relating to the winding which consists of one primary and two opposite secondary windings. The output voltages may reach 15,000 Volts with maximum secondary short circuit currents of 300 mA.

Such a type of product may have secondary windings with quadrangular shapes which mean that during winding the wire is subject to bending conditions which may locally and significantly influence its initial characteristics. Moreover, such deviations may be further enhanced when transformers with small dimensions are to be obtained or in any case in line with the strictest product and installation regulations. Therefore, in this case there are many variables to consider, and they have many mutual influences. It is important to take into account the most suitable copper cross-section; the most suitable covering films for insulation and covering hardness; the copper material with the most suitable stretching must be selected; sufficient electric rigidity both at ambient temperature and at high temperatures; the covering with a maximum number of leaks on the insulating film complying with the relevant regulation; and/or a material with a number of other defects created during laying of the film and in compliance with the relevant regulation.

These are characteristics which often lie partly or fully outside the specific distinctive regulations relating only to standard enamelled wires and which do not correspond to the needs, which are more complex and of various types (design-related, technological, environmental, etc.) relating on each occasion to the specific electrical equipment as a whole; regulations which, in short, cannot suitably aid the designer, meaning that in practice designers must use specific specifications which vary in type from one product to the next.

The example just discussed makes it clear that, after the production process, the characteristics of a wire for a predetermined product may change locally and/or diffusely, and deviate from the reference values initially envisaged to different final values, sometimes to such an extent that they do not meet the requirements initially envisaged. In the production environment, said phenomenon makes it necessary to use lengthy processes for finding and setting up the best production operating conditions capable of resulting hi the achievement of the desired standard of quality only with numerous attempts and many corrections, which require long and expensive set up times, inevitably having a negative effect on the final costs of the product.

Moreover, such a way of operating also has the fundamental disadvantage of allowing the identification of correctives for the design data by obtaining information from the product when it is practically finished, which, in the case of wire windings, is rather inadequate relative to the considerable length of the wire usually used in each winding and the high risk that such a winding may have problems if there are very localised defects.

This means that prior art production techniques are subject to production and control methods that are not only quite approximate, but which for producers of electrical equipment keep high the risk of producing potentially faulty equipment, not completely reliable and not durable enough, with disadvantages as regards low costs of production and liability for damages that are easy to imagine.

Disclosure nf the. Invention

The main aim of the invention is to overcome the afore-mentioned disadvantages by providing a production process able to simulate use of the enamelled wire, that is to say, to simulate the windings in such a way as to allow studying in advance of the consequent phenomena and their influences on significant product parameters; and/or able to measure simulated and/or actual losses of characteristics; and/or able to control on-line, during the production process, several characteristics of the enamelled wire in such a way that they can be suitably managed to obtain predetermined performance on the electrical equipment for which the winding is intended.

The technical solution, in accordance with the above aims, has technical features which are clear from the content of the claims herein, in particular claim 1, and from any of the claims directly or indirectly dependent on claim 1.

Rrief Description nf the Drawings

The advantages of the present invention are more apparent in the detailed description which follows, with reference to the accompanying drawings which illustrate preferred, non-limiting embodiments of the invention, in which: - Figure 1 is a functional block diagram showing a first embodiment of the system in accordance with the invention;

Figure 2 is a functional block diagram showing a second embodiment of the system;

Figure 3 is a block diagram of a section of the system which can advantageously be integrated in the diagrams of Figures 1 and 2.

Detailed Description nf the Preferred F.mhnriimertts nf the Invention

With reference to the accompanying drawings, Figures 1 is a block diagram of a piece of equipment which corresponds to a first embodiment of the system in accordance with the invention, labelled 100 as a whole.

The piece of equipment 100 comprises a block 105 identifying a wire stretching apparatus, in particular of the electronic type, with a relative control that can be set according to requirements for the preliminary study of the characteristics of the wire, for controlling the wire characteristics, or for simulating particular wire stretching intensities. The block 104 identifies an apparatus for guiding and stabilising the wire before it is fed into a subsequent block labelled 103.

The block 103 symbolically represents an apparatus for reading the external diameter of the wire, an apparatus which in particular may comprise an optical micrometer, designed to detect the diameter of the wire on two crossed axes, also identifying wire section outline ovalisation. The reading apparatus, preferably electronically-controlled, can also acquire data on-line.

The piece of equipment 100 also comprises a first block 101 symbolically representing as a whole a wire winding unit, with a set of motor-driven spindles, equipped with layering means and managed by electronic control means operated, for example, by a programmable logic controller, hereinafter referred to briefly as a PLC.

The rotary spindles may have various shapes and sizes. For example, they may be cylindrical or quadrangular, depending on requirements and the features of the electrical equipment for which they are intended. The functional operating parameters of the rotary spindles can be set using the PLC in various ways, depending on whether or not winding is performed to be studied, for example in a preliminary way to find the optimum operating conditions for subsequent production, or for controlling the actual operating conditions of current production, or to simulate winding and/or steps in its progress.

The block 107 indicates a hardware unit for controlling the entire piece of equipment, housed in a supporting structure.

The block 113 indicates as a whole software means supplied with the system 100 disclosed. The software means operate in ways symbolically represented with a block 108 identifying a software for simulating winding phenomena, acceleration and deceleration ramps of winding spindle motion - stop transients, as well as ramps for wire layering in the winding as a whole. The block 109 symbolically identifies a PLC control software unit which controls and checks the winding spindles. The block 110 identifies a software unit for detecting data and organising it, from the PLC, from the optical micrometer of block 103, from the electronic wire stretcher of block 105.

The block 113 also comprises a block 111 identifying a software for management of an archive of data about internal control specifications (SPI) and which can activate a process control (APC) which substantially compares the data relative to the expected technical characteristics and that relative to the actual technical characteristics of the wire (operator data, machine data, times, materials) and which prevents use of the wire if it does not conform to the specifications.

Finally, the block 112 identifies a software product which designs, simulates, organises and manages all of the various areas of the system.

In particular, the piece of equipment 100 being used allows, through the software means relative to block 108, mechanical and dynamic modelling for simulating actual winding, setting the operating data for example according to the type of wire, the type of support for its winding, the distances between the operating elements used for winding (shuttle, wire guide and wire stretcher), operating angles between the elements, operating element accelerations and decelerations, spindle speed of rotation: these parameters all, over time and in varying degrees and different ways, being able to influence the initial characteristics of the wire (detected and saved in the relative archives), modifying them to a greater or lesser extent during the winding process. In particular, use of the software relative to block 108 allows the following to be identified: torque, radial force, tangential force, axial force and tension applied to the wire at the various moments of the winding process.

These characteristics in particular allow control of winding in system actual production, for optimum compliance of the electrical product for which the winding is intended with the highest performance and reliability specifications required. Figure 2 shows a second embodiment of the system - labelled 200 as a whole - comprising a block 204 and a block 203 identifying as a whole an apparatus for guiding and stabilising the wire before it reaches an apparatus 300 for reading the diameter, not illustrated in the accompanying drawings, which operates similarly to that shown in Figure 1 with the block 103, but unlike the latter consists for example of an optical microscope, supported by suitable software, for measuring diameters, identifying ovalisation and using enlargement to detect surface faults on the wire. Blocks 204 and 203 also symbolically represent operations which are similar to those already described relative to Figure 1, therefore, a detailed description is not provided here.

Blocks 212 and 213 symbolically represent gauges which allow the wire to run on special "V"-shaped guides, fully known and defined by specific dimensional testing standards: standards which make a distinction between two different wire size ranges which can refer symbolically to one or the other of the blocks.

Block 211 symbolically represents a measuring instrument for measuring insulation continuity at a high voltage. For the two size ranges with different wire thickness, relative to blocks 212 and 213, this instrument is used to detect the insulation continuity with a specific electric test circuit.

The blocks 210 and 209 symbolically represent, respectively, pieces of equipment 210 allowing the wire to run on pieces of felt soaked with saline solution and a test instrument with which, by means of a specific electric test circuit, it is possible to measure the insulation continuity for the length of the wire detected.

The system 200 also comprises blocks 201, 202 and 219 which, similarly to what was said relative to Figure 1 , respectively symbolically represent: wire winding on a set of motor-driven spindles having various shapes, controlled by a PLC (Blocks 201 and 202). Again, the operating parameters with which winding is performed are controlled by control software (Block 219) which, similarly to what has already been said relative to Figure 1, can be set according to various requirements: for studying, controlling and simulating winding.

The system 200 of Figure 2 also comprises a block 208 symbolically representing equipment for PLC management and control of temperatures, on a test gauge, for high voltage puncturing of the wire covering. Two other blocks 206 and 207 identify two types of test: the first at ambient temperature, the second at a high temperature.

The block 205 symbolically represents a test instrument which, with reference to the two conditions relative to blocks 206 and 207, detects the puncture voltage and relative current, using a specific electric test circuit. The blocks 214 and 215 respectively identify an instrument for detecting the direct current electrical resistance at 2O⁰C of a predetermined length of copper wire; and a specific piece of equipment for that test.

The block 230 identifies software means which manage the system 200. The means 230 include blocks 217 and 218 respectively identifying: the hardware for controlling the entire piece of equipment and a software module that operates similarly to the block 118 of Figure 1 , simulating winding and setting the operating data, hi the present embodiment of the system 200 the software means 230 also include a block 220 symbolically identifying a software for detecting data relating to: PLC, electronic wire stretcher, resistance, puncturing at ambient and high temperature, and insulation continuity at low and high voltage. hi block 230 there are also blocks 221 and 222, similar to blocks 111 and 112 of Figure 1, therefore, a detailed description is not provided here.

Irrespective of the embodiment - in Figure 1 or Figure 2, - the system 100 or

200 may advantageously also include a piece of equipment for managing the wire mechanical characteristics. Said piece of equipment is illustrated in Figure 3 and labelled 300 as a whole. It comprises blocks 301, 302, 320 interfacing with the software means, which for the different embodiments are represented with the block 113 or 230.

The block 301 symbolically represents an apparatus for ultimate elongation and ultimate tensile strength tests on the wire.

The block 302 symbolically represents an apparatus used for spring-back tests, that is to say, to identify the unwinding measured in degrees that the wire wound in the shape of a spiral coil can adopt once it is left free.

The block 320 symbolically represents with the block 303 the spindles for spring-back tests; with the block 304 spindles for testing wire flexibility and adherence and with block 305 spindles for wire heat shock tests. A block 306 symbolically represents a crucible apparatus for testing loss of mass relating to the wire covering and indicating its degree of polymerisation.

The system disclosed fully achieves the aim of being able to measure, analyse and control all electrical, mechanical and technological characteristics of the wire both on acceptance and during the production process so as to manage the production operating parameters flexibly and in real time in such a way as to give the electrical product for which they are intended windings of the highest production quality and the best level of reliability in use.

The invention described above is susceptible of industrial application in many sectors of use and, in particular in the sector of electrical equipment with components using wire wound in coils. The invention described may also be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements.

Claims

1. A system for producing enamelled copper wire windings for electrical equipment, characterised in that it comprises the steps of: setting data identifying significant characteristics of the wire; preliminary measurement of significant characteristics of the wire and allocation of said data and measurements taken to a suitable storage archive; feeding a winding section, equipped with at least one rotary spindle, with a continuous copper wire that has a circular cross-section; measuring the significant characteristics of the wire at least regarding their part susceptible to modification during the production process; comparing at least said characteristics with the data held in the storage archive, identifying any deviations; according to said deviations, identifying operating parameters for the winding section; and managing the winding section based on the operating parameters saved.

2. The system according to claim 1, characterised in that the measuring steps comprise measurement of characteristics selected in the families of measurements of wire external diameter, electrical resistance, insulation continuity at low and high voltage, puncture voltage at ambient and high temperature, ultimate elongation, ultimate tensile strength, spring-back, flexibility and adherence of the enamel on the wire, heat shock, loss of wire mass.

3. The system according to claim 2, characterised in that the steps of measuring the external diameter of the wire are carried out using an optical micrometer.

4. The system according to claim 2, characterised in that the steps of measuring the characteristics, selected in the family of measurements of ultimate elongation, ultimate tensile strength, spring-back, flexibility, adherence of the enamel on the wire, heat shock and loss of mass, are carried out on a piece of wire wound by the one or each spindle.

5. The system according to any of the foregoing claims, characterised in that the winding section comprises a plurality of rotary spindles.

6. The system according to claim 5, characterised in that the steps of measuring the characteristics, selected in the family of measurements of the external diameter, are carried out in the entire angular extension of the cross-section of the wire.

7. The system according to claim 6, characterised in that the measurements of the external diameter are carried out using an optical microscope.

8. The system according to claim 6 or 7, characterised in that the steps of measuring the external diameter include a step of detecting faults on the covering surface of the wire.

9. The system according to claim 2, characterised in that the steps of measuring the characteristics, selected in the family of measurements of ultimate elongation, ultimate tensile strength, spring-back, flexibility and adherence of the enamel on the wire, heat shock and loss of mass, are carried out on a piece of wire wound by the one or each spindle.

10. The system according to claim 9, characterised in that the measuring steps are carried out at the end of winding and during rotation on the one or each spindle.

11. The system according to claim 1 , characterised in that the step of managing the winding section comprises suitable management of acceleration and deceleration ramps for the winding spindles.

12. The system according to claim 1 or 11 , characterised in that the step of managing the winding section comprises suitable management of layering ramps for the wire during winding.

13. The system according to claim 11 or 12, characterised in that the step of managing the winding section is carried out in conformity with methods previously identified using software simulation.