DEVICE AND METHOD FOR REMOVING AN INSULATING LAYER ON A LENGTH SECTION OF A WIRE

Description

[0001] The invention relates to a device for removing an insulating layer from a length section of a wire for forming a coil winding of an electric machine. The invention further relates to a method for removing an insulating layer from a length section of a wire for forming a coil winding of an electric machine.

[0002] For technological background, please refer to the following literature: [1] EP 2 684 283 B1 [2] EP 1 554 794 B1 [3] EP 1 041 696 B1 [4] WO 2019 / 161 832 A1 [5] WO 2019 / 101 272 A1 [6] WO 2019 / 020148 A1 [7] WO 2019 / 166061 A1 [8] DE 10 2018 106 977 A1 [9) US 11 018 482 B1

[10] EP 3 758 167 A1

[0003] Electrical machines are understood to be machines for converting electrical energy into kinetic energy and machines for converting kinetic energy into electrical energy. Electric motors and generators are particularly examples. The production of machine elements for such electrical machines, such as stators or rotors, often requires forming, joining, cutting, or otherwise processing electrically conductive wires. The wire can have a rectangular cross-section, be flat, square, or profiled, or be, for example, flat steel strip or similar material. The production of these machine elements typically takes place in a manufacturing plant where wire made of electrically conductive material is processed.Thus, when manufacturing a machine element of an electric machine, a continuous introduction of material into the manufacturing process can be achieved, leading to high productivity.

[0004] The production of electric motors for motor vehicles mostly uses industrial series production processes with high cycle rates, which enable particularly economical manufacturing of high-performance components for electric motors.

[0005] Examples of production processes in which the device and method according to the inventive embodiments are applicable are the hairpin process and the wave winding process. In the particularly preferred hairpin process, coil windings, especially of the stator, are formed from different pieces of wire whose ends are joined together. For example, references [1] to [4] describe devices and methods for carrying out different steps of the hairpin process, such as, in particular, forming hairpins and joining the wire ends of hairpins to form stator windings of electrical machines, in which the wire ends are welded together.In the wave winding method, examples of which are known from references [4] to [7], in particular the ends of the wave windings are connected to each other or to a connecting element for connecting the coil winding, in particular by welding.

[0006] The starting material for manufacturing the various coil windings is typically a copper wire coated with an insulating layer. This insulating layer is primarily made of plastic. It is usually a rectangular wire (e.g., made of copper or another metal) with rounded edges. Welding the individual coil winding sections, such as hairpins or wave winding wires, together to form a continuous winding is a crucial manufacturing step. A prerequisite for a flawless weld is that the two ends to be joined have no insulating layer over a defined length. The insulating layer, which is often an insulating lacquer coating, is primarily removed by scraping or planing. This can be done either lengthwise or crosswise along the wire.Examples of known devices and methods for removing insulation are disclosed in reference [8].

[0007] Preferred embodiments of the invention lie in the field of electric motor manufacturing using the hairpin process and relate to the removal of an insulating layer from a wire, usually copper wire. As explained above, in the hairpin process the wire is first bent into hairpins (i.e., a piece of wire in a form with a first and a second leg, where the wire runs essentially straight, and with a generally roof-shaped, three-dimensionally formed connecting section between the legs, which in use forms a winding head) and the individual hairpins are subsequently welded together, for which the insulating layer must first be removed at the weld point. Various methods are already known for this purpose, which, for example, remove the insulating layer by laser ablation, milling, or scraping.

[0008] Stripping the wire by milling produces a large number of small chips that are difficult to remove from the hairpin wire. Poor quality and contamination of the milled surfaces could lead to defects in the weld formation. Preferred embodiments of the invention should therefore enable stripping by scraping in order to improve the quality and cleanliness of the stripped areas.

[0009] A method for scraping off the insulation layer is disclosed in [9], wherein the insulation layer is removed by a pair of peeling blades positioned orthogonally to the wire direction. The wire is held by opposing grippers, the movement of the cutting edges towards the wire also causing the grippers to be positioned.

[0010] Reference

[10] describes a device for scraping insulation material, in which four blades are mounted on individual holders, with two blades working together. By actuating the holders, all four sides of the wire are clamped by the blades. Subsequently, the platform with the copper wire is moved, causing the coating to be scraped off by the four positioned blades.

[0011] The invention aims to enable high-quality, high-speed stripping.

[0012] To solve this problem, the invention provides a device according to claim 1 and a method and a computer program according to the dependent claims.

[0013] Advantageous embodiments are the subject of the dependent claims.

[0014] The invention provides a device for removing an insulating layer from a longitudinal section of a wire for forming a coil winding of an electrical machine, comprising: A wire guide for guiding the wire to be processed through it in a wire movement direction; a slide arrangement with several slides arranged around the wire to be guided through the wire guide and which are radially displaceable back and forth relative to the wire guided in the wire guide, wherein at least one cutting slide with a cutting edge for scraping off the insulation and at least one counter-bearing slide for holding the wire in place during scraping are provided such that a cutting slide and a counter-bearing slide are opposite each other and are movable towards and away from each other, and a cam disk with a central opening through which the wire can be guided by means of the wire guide.wherein the cam disk is rotatable by means of a cam disk drive and has a first at least partially annular control cam section for controlling and / or driving the movement of the at least one cutting slide and a second at least partially annular control cam section for controlling and / or driving the movement of the at least one counter-bearing slide.

[0015] It is preferred that the slide arrangement comprises at least two of the cutting slides and at least two of the counter-bearing slides.

[0016] It is preferred that the first and second control curve regions are different regions of a common control curve that is at least partially or completely annular.

[0017] It is preferred that the first control cam area and the second control cam area are formed on axially or radially spaced different control cams.

[0018] It is preferred that the first control cam section is formed by a first annular control cam for controlling and / or driving the movement of several, preferably all, cutting slides, and that the second control cam section is formed by a second annular control cam for controlling and / or driving the movement of several, preferably all, counter-bearing slides. Preferably, each cutting slide engages the first control cam of the cam disk at different, circumferentially spaced locations. Preferably, each counter-bearing slide engages the second control cam of the cam disk at different, circumferentially spaced locations.

[0019] It is preferred that the cam disc is rotary-driven by means of a servo drive controlled by an electronic control unit as a cam disc drive.

[0020] It is preferred that the cam disc is connected to the cam disc drive by means of a continuous drive, in particular a belt drive. Preferably, a positive-locking continuous drive is provided, for example a toothed belt drive.

[0021] It is preferred that the control cam regions and / or the control cams are formed by surfaces on the cam disk extending in a circumferential and an axial direction. It is preferred that the control cam regions or control cams are designed as axially projecting ridges, wherein the sliders have pairs of cam follower elements, in particular pins or cam rollers, which accommodate the associated ridge between them. Of course, other designs and arrangements of control cams are also possible; for example, the control cams or control cam regions, or one of them, can also be designed as recesses, grooves, slots, or outer edge surfaces on the cam disk. The cam disk can also be annular, with an inwardly directed surface extending in a circumferential and an axial direction serving as the control cam.

[0022] It is preferred that the slider arrangement has sliders arranged evenly in a circle around the center in which the wire is guided.

[0023] It is preferred that the slide arrangement has a first to fourth slide.

[0024] It is preferred that the slide arrangement has a first to eighth slide.

[0025] It is preferred that the slide arrangement comprises several pairs of radially opposed slides with a cutting slide and a counter-holding slide.

[0026] It is preferred that the slide assembly be movable intermittently with the wire. In particular, the slide assembly, or a stripping or scraping device comprising the slide assembly, is movable back and forth in a linear direction parallel to the wire in order to move with the wire. This movement is preferably achieved by means of a suitable motion mechanism with at least one actuator controlled by a control unit. The movement is preferably such that, despite the wire continuing to move (e.g., continuously or with pulsating motion), there is no relative movement between the slide assembly and the wire. Preferably, the device is configured so that not only the slide assembly, but the entire stripping or scraping device, including the cam and, if applicable, the cam drive, moves with the wire.In particular, the control unit is designed to control the movement mechanism to move the stripping or scraping device synchronously with the wire.

[0027] It is preferred that the cutting slide(s) each have a set of knives with several knives designed to scrape the insulation on opposite sides of the wire.

[0028] It is preferred that the at least one cutting slide (in particular a single provided cutting slide or each of several cutting slides) per knife has a guide element which is guided around a knife edge of the knife and has a height offset to the knife by which the penetration depth of the knife into the wire can be determined.

[0029] It is preferred that the at least one cutting slide (in particular a single provided cutting slide or each of several cutting slides) has an ejection element elastically pre-tensioned in an ejection position to assist in ejecting the wire from the knife set.

[0030] It is preferred that the at least one cutting slide (in particular a single provided cutting slide or each of several cutting slides) has a tuning disc between the knives for adjusting the knife spacing.

[0031] It is preferred that the knife set includes a first and a second knife.

[0032] It is preferred that the knife set comprises knives each formed from a hard metal plate with a pointed shape.

[0033] It is preferred that the knife set has knife cutting edges on the knives whose tips are chamfered to form a wedge angle.

[0034] It is preferred that the counter bearing slide(s) each have a counter bearing element for contact with the wire.

[0035] It is preferred that the counter bearing slide(s) each have guide jaws for pre-positioning the wire.

[0036] Preferably, the device has an electronic control unit - in particular a computing unit or computer such as an ECU, microcontroller or a software or hardware component of an overall control system for a larger production plant - which is designed to control the device to perform the following steps in a timed manner: a) Moving the device and the wire to be processed relative to each other in its longitudinal direction, so that the wire moves relative to each other through the center of the slider arrangement; b) stopping the relative movement; c) rotating the cam disk to drive the sliders to scrape off the insulation; and repeating steps a) to c) to strip the wire on another length.

[0037] In one embodiment, in step a) the wire is moved through the stationary device or assembly, then in step b) the wire movement is stopped, and then step c) is carried out while the wire is stopped. In preferred embodiments, at least the slider assembly or a larger unit – such as, in particular, the stripping or scraping device – of the device, or the entire device, is designed to be movable and configured to move synchronously with the preferably continuously moving wire to carry out step b), so that the slider assembly is stationary relative to the wire to carry out step c).

[0038] It is preferred that the control unit is configured to drive the device, when performing step c), to rotate the cam disk by at least one complete revolution in order to successively drive the slides for scraping off the insulation.

[0039] According to another aspect, the invention provides a method for removing an insulating layer from a longitudinal section of a conductor for forming a coil winding of an electrical machine, comprising: providing a device according to one of the preceding claims, and sequentially performing the steps: a) Moving the device and the wire to be processed relative to each other in its longitudinal direction, so that the wire moves relative to each other through the center of the slider arrangement, and b) stopping the relative movement and c) rotating the cam disk to drive the sliders to scrape off the insulation; and repeating steps a) to c) to strip the wire on another length.

[0040] Preferably, a device is provided with at least two cutting slides and at least two counter-bearing slides, wherein step b) comprises: rotating the cam disk by at least one complete revolution to successively drive the slides to scrape off the insulation.

[0041] In one embodiment of the device and / or the method, in step a) the wire is moved through the stationary device, then in step c) the wire movement is stopped, and then step c) is carried out while stopped. In preferred embodiments, at least the slide assembly, or a larger unit or component of the device, or the entire device, is designed to be movable and configured to move synchronously with the preferably continuously moving wire to carry out step b), so that the slide assembly is stationary relative to the wire to carry out step c).

[0042] According to another aspect, the invention creates a computer program comprising commands that cause the device according to one of the preceding embodiments to execute the process steps of the method according to one of the preceding embodiments.

[0043] Preferred embodiments of the invention relate to a device and a method for stripping a hairpin wire by scraping transversely to the wire direction.

[0044] Preferred designs enable scraping even in very fast industrial mass production with very short cycle times.

[0045] Preferred designs allow cross-scraping on a relative stop of wire and stripping unit with a cycle time of 1s or less.

[0046] A stop means that the wire has no relative movement to the described unit during the process and is therefore stationary. This can be achieved by stopping the wire, but preferably by moving the stripping device along with it.

[0047] Preferred embodiments of the invention have one or more of the following advantages: Stripping an endless wire (especially hairpin wire, but also suitable for stripping the ends of wave-wound wires) in just one stop, cycle time of one second (e.g., 0.4 seconds for stripping, 0.6 seconds to move the device or setup to the next stripping point), only one servo motor is required.

[0048] Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 a schematic side view of an embodiment of a device for removing an insulating layer from a length section of a conductor, comprising a device for removing an insulating layer from a length section of a conductor, a movement mechanism for moving the device, and a control unit; Fig. 2 a front view of an embodiment of the device for removing an insulating layer from a length section of a conductor in the form of a wire, viewed against the wire feed direction (direction of movement of the conductor / wire); Fig. 3 a rear view of the device of Fig. 2 Viewed in the wire feed direction; Figs. 4 and 5 are perspective views of the setup. Fig. 2 and 3 Fig. 6 shows a perspective view of a slide arrangement, a cam disk and a cam disk drive of the device according to the Figs. 2 to 5Fig. 7 is a front view in the wire-trapping direction, showing a detail of the center of the slide assembly, with all slides of the slide assembly in their home position and out of engagement with the wire; Figs. 8 and 9 are perspective views of the detail of Fig. 7 ; Fig. 10 a view as in Fig. 8 , wherein a pair of radially opposing sliders of the slider assembly are in an engagement position in engagement with the wire; Fig. 11 a front view as in Fig. 7 at also in Fig. 10Fig. 12 shows the engagement of the pair of slides with the wire, wherein the pair of slides comprises a cutting slide and a counter-bearing slide; Fig. 13 shows a front view of the pair of slides in the home position; Fig. 14 shows a partially cut-out perspective view of the device to illustrate the formation of the cam disc; Fig. 15 shows a perspective view of the front end of the counter-bearing slide facing the wire; Fig. 16 shows a perspective view of the front end of the cutting slide facing the wire; Fig. 17 shows a top view of a blade of a blade set of the cutting slide; Fig. 18 shows a front view of the blade of Fig. 17Fig. 19 a front view of the knife set; Fig. 20 a top view of a guide element of the cutting slide; Fig. 21 an enlarged front view of a detail of the front end of the cutting slide, showing a pair of guide elements with an ejection element in the ejection position between them; Fig. 22 a partially broken-off top view of the front end of the cutting slide to illustrate the design of the ejection element; Fig. 23 a front view of the arrangement of the pair of guide elements with the ejection element; Fig. 24 a sectional view of a cutting edge of the cutting slide with the arrangement of Fig. 23 and the knife set; Fig. 25 a cross-section through the length section to be stripped before stripping; and Fig. 26 the same cross-section as in Fig. 25 after stripping.

[0049] Fig. 1Figure 10 shows a schematic block diagram of a device 10 for removing an insulating layer 12 from a longitudinal section 18 of a conductor for forming a coil winding of an electrical machine. The device 10 is designed to remove the insulating layer 12 from a wire 14 provided with an insulating layer 12 at predetermined locations (example shown in section in Figure 1). Fig. 26 (as shown), to strip off a length section 18 in each case. A wire section located between successive stripped length sections 18 can be formed in later process steps, as described and shown in [1] to [7], into a conductor of the coil winding of the electrical machine, for example into a hairpin of a stator to be manufactured according to the hairpin method.

[0050] The device 10 comprises a (stripping or scraping) device 16 for removing the insulating layer 12 from the longitudinal sections 18, a movement mechanism 20 for moving the device 16, and a control unit 22. The control unit 22 is designed as an electronic control unit (computer) with a processor 22a, a memory 22b, and a computer program stored therein. The control unit 22 can, for example, be part of an overall control system for a bending machine (e.g., a hairpin bending machine for producing bent hairpins) or for an entire production system for manufacturing a component of the electric machine; see also [1] to [7].

[0051] The device 10 has a wire guide 24 designed to guide the wire 14 as an endless wire through the device 10 in the direction of wire movement 26. In particular, the wire guide 24 is designed to guide the wire 14 through the device 10. The wire movement can be continuous, pulsating, or pulsed. The movement mechanism 20 is designed to move the device 16 along with the moving wire 14, so that the device 16 and the wire 14 are stationary relative to each other for the stripping process, which will be explained in more detail below. For this purpose, in the illustrated purely exemplary embodiment, the movement mechanism 20 has a slide or carriage 30 that is movable on a machine frame 28 and can be moved back and forth by means of a motion actuator 32 controlled by the control unit 22. The device 16 is mounted on the carriage 30.

[0052] In the Figs. 2 to 5Different views of the device 16 are shown. The device 16 has a slide arrangement 34, a cam disk 36 and a cam disk drive 38. Furthermore, a wire guide unit 40 of the wire guide 24 is provided in the center of the device.

[0053] In the illustrated embodiment, the device 16 further comprises a base frame 42 (e.g., designed as a welding console) which can be attached to the slide or carriage 30 of the movement mechanism 20 by means of a base 44. The base frame 42 further comprises a mounting plate 46 which extends perpendicular to the wire movement direction 26.

[0054] The wire guide unit 40 is guided centrally through the mounting plate 46 and has, for example, a guide tube 48 through which the wire 14 is guided. For example, the guide tube 48 is arranged inside a suction tube 50 for extracting scraped material from the insulation layer 12, the suction tube 50 opening towards the center of the slide assembly 34.

[0055] The slide assembly 34 comprises several slides 52.1-52.8, which are mounted on the mounting plate 46 so as to be displaceable radially towards and away from the wire guide unit 40. The slides 52.1-52.8 are arranged in opposing pairs, such that at least one pair 54.1 of slides 52.1, 52.2 and preferably at least two pairs 54.1, 54.2 of slides 52.1-52.4 are provided. The illustrated embodiment of the device 16 has a first to fourth pair 54.1-54.4 of slides 52.1-52.8. Each pair of slides 54.1-54.4 has a cutting slide 56 and a counter-bearing slide 58. Thus, a cutting slide 56 and a counter-bearing slide 58 are radially opposite each other and are movable between a basic position in which the slides 52.1-52.8 are moved radially outwards and are out of engagement with the wire 14, and an engagement position in which the slides 52.1-52.8 of the respective slide pair are in engagement with the wire 14.In the embodiments shown in the figures, the first, third, fifth, and seventh slides 50.1, 50.3, 50.5, and 50.7 are designed as cutting slides 52, and the second, fourth, sixth, and eighth slides 50.2, 50.4, 50.6, and 50.8 are designed as counter-bearing slides 54. Each cutting slide 56 is provided with at least one cutting edge 60 for scraping off the insulation. The respective counter-bearing slide 58 is designed to hold the wire in place during scraping. Thus, each cutting slide 56 and counter-bearing slide 58 are positioned opposite each other and can be moved towards and away from each other.

[0056] The cam disk 34 has a recess or opening, in particular a central opening 62, through which the wire 14 can be guided by means of the wire guide 24. In particular, the guide tube 48 and especially the suction tube 50, which is concentrically provided with the guide tube 48, extend through the central opening 62. The cam disk 36 is rotatably mounted on the mounting plate 46. In the illustrated embodiments, the cam disk 36 is rotatable about the center of the guide tube 48 and thus about the center of the wire 14 guided therein.

[0057] The rotation of the cam disk is driven by the cam disk drive 38, which is controlled by the control unit 22. The cam disk 34 has at least one mechanical control cam 64.1, 64.2 extending in a circumferential direction. On the at least one control cam 64.1, 64.2, a first control cam section, at least partially annular (extending, for example, in a circumferential direction at least over a ring sector), is formed for controlling and / or driving the movement of the at least one cutting slide 56. Furthermore, on the at least one control cam 64.1, 64.2, a second control cam section, at least partially annular (extending, for example, in a circumferential direction at least over a ring sector), is provided for controlling and / or driving the movement of the at least one counter-bearing slide 58.

[0058] If, as shown, several pairs of slides 52.1-52.4 are provided, their cutting slides 56 are arranged at different tangential positions around the wire 14 guided by the wire guide 24, and the counter-bearing slides 58 are positioned opposite them. All cutting slides 56 engage the first control cam section 66.1 at different circumferentially spaced locations. Furthermore, all counter-bearing slides engage the second control cam section 66.2 at different circumferentially spaced locations. Thus, when the cam disk 36 is rotated, the movements of all slides 52.1-52.8 are driven.

[0059] In some embodiments, the cam drive 38 is designed as a servo drive controlled by the control unit 22. Furthermore, in some embodiments, the cam 36 is connected to the cam drive 38 by means of an endless belt drive, in particular a belt drive 68. The belt drive 68 has, for example, a toothed pulley 68a on the output shaft of a servo motor of the cam drive 38 and a toothed belt 68b, wherein the cam 36 has a toothed pulley section 68c with teeth on which the toothed belt 68b engages in a positive-locking manner.

[0060] The illustrated embodiment of the device 10 is designed to strip an endless hairpin wire 14 of a specific length (e.g., 10 to 50 mm, in particular 40 mm) on all four sides and radii. The stripping process can also be performed at a standstill. In the illustrated embodiment, a standstill is achieved by a cycle of relative stillness – while the device 16 moves along with the wire 14. Fig. 2 This shows a view against the wire clock direction - wire movement direction 26 - and Fig. 3 shows a view in wire clock direction - wire movement direction 26.

[0061] The following will refer to the Figs. 6 to 13 Reference is made to the figures, which show different views of the slide arrangement 34 and the cam disc 36. The slides 52.1-52.8 are located in the illustrations of the Figs. 6 to 8 as well as 12 and 13 in the basic position, and in the representations of the Fig. 10 and 11The slides 52.5, 52.6 are one of the slide pairs, here e.g. of the third slide pair 54.3 intended for scraping the smaller side surfaces of the rectangular wire in the engagement position.

[0062] The stripping device 16 of the embodiment of the apparatus 10 shown here essentially consists of eight slides 52.1-52.8, mounted on a welding bracket (example of base frame 42). In the illustrated embodiment, the slides 52.1-52.8 are arranged uniformly in a circle at an angle of 45° and can be moved radially (linearly) inwards towards the center. Two opposing slides 52.1, 52.2; 52.2, 52.3; 52.4, 52.5; 52.5, 52.6; 52.7, 52.8 form a pair 54.1-54.4 consisting of a counter-bearing slide 58 with a counter-holder 78 and a cutting slide 56 with at least one cutting edge 60.

[0063] How to present the Fig. 6 and13 As can be seen, the first control cam section 66.1 and the second control cam section 66.2 are formed on different control cams 64.1, 64.2. In some embodiments (not shown), the different control cams are axially spaced apart, e.g., arranged on different sides of the cam disk. In the embodiments shown, the first and second control cams 66.1, 66.2 are radially spaced apart, with an inner and an outer control cam being formed.

[0064] In the illustrated embodiments, the first control cam section 66.1 is designed as a circumferentially extending surface area along the entire length of the first, here annular, control cam 64.1, which is designed to control and / or drive the movement of all four cutting slides 56. The second control cam section 66.1 is designed as a circumferentially extending surface area along the entire length of the second, here annular, control cam 64.1, which is designed to control and / or drive the movement of all counter-bearing slides 58. Preferably, the first control cam 64.1 is formed by a first bead 72.1, preferably annular. Preferably, the second control cam 64.1 is formed by a second bead 72.2, preferably annular.

[0065] In the illustrated embodiments, the control cams 64.1, 64.2 are thus designed as axially projecting ridges 72.1, 72.2. The slides 52.1-52.8 each have pairs of cam follower elements, in particular pins or cam rollers 74, which accommodate the associated ridge 72.1, 72.2 between them. The majority of the circumferential control cams 64.1, 64.2 are annular in shape to hold the slides 52.1-52.8 acting on them in their home position. At one point on its circumference, the first control cam 64.1 has a radially inwardly extending first indentation 76. At the point radially opposite to the first indentation 76.1, the second control cam 64.2 also has an inwardly extending second indentation 76.2. When the cam disk 36 rotates, the pair of cam rollers 74 of the opposing sliders 52.5, 52.6 of a slider pair 54 passes through the mutually directed indentations 76.1, 76.2.3 (for example, the third pair of slides 54.3 in the figures), then the respective cutting slide 56 and the associated counter-bearing slide 58 are moved from their initial position to their engagement position relative to each other. Due to the different circumferential contours of the first and second ridges 72.1, 72.2 relative to their respective positions, the surface profiles at the first indentation differ from those of the second indentation 76.1, 76.2 in order to cause the cutting slide 56 and the associated counter-bearing slide 58 to move at different times. The surface profiles—i.e., the profiles of the control cam sections 66.1, 66.2 and control cams 64.1, 64.2—are such that the movement sequences of the slides 52.1–52.8 and their elements, as described below, are achieved.

[0066] Accordingly, in some embodiments, cam rollers 74 of all slides 52.1-52.8 are engaged with one of two ridges 72 located on the cam disk 34. In the illustrated embodiment, four counter-bearing slides 58, 52.2, 52.4, 52.6, 52.8 are engaged with a second ridge 72.2 forming the second control cam 64.2, while four cutting slides 56, 52.1, 52.3, 52.5, 52.7 are engaged with the first ridge 72.1 forming the first control cam 64.2. The cam disk 34 is moved by means of a belt drive 68 and a servo motor.

[0067] The first pair of sliders 54.1 with the first and second sliders 52.1, 52.2 is for scraping the larger side surfaces 112 of the rectangular-section wire 14 (see Figs. 25 and 26). The second pair of sliders 54.2 with the third and fourth sliders 52.3, 52.4 is designed for scraping off corner edges 114 adjoining the larger side surfaces 112 in one circumferential direction. The third pair of sliders 54.4 with the fifth and sixth sliders 52.5, 52.6 is designed for scraping off the smaller side surfaces 116 of the rectangular-section wire 14 (see Figs. 25 and 26 ) formed. The fourth pair of sliders 54.1 with the seventh and eighth sliders 52.7, 52.8 is designed for scraping off corner edges 118 adjoining the larger side surfaces 112 in the other circumferential direction.

[0068] In the illustrated embodiment, during a scraping process, the slider pairs 54.1-54.4 are actuated such that first the side surfaces 112, 116 are scraped (in any order) and then the corner edges 114, 118 are scraped (in any order). For example, in the illustrated embodiment, the slider pairs 54.1-54.4 are actuated in the sequence: first slider pair 54.1 - third slider pair 54.3 - second slider pair 54.2 - fourth slider pair 54.4.

[0069] The method for removing the insulating layer on length sections 18 of the conductor designed as wire 14, which can be carried out using the device 10, comprises the following steps: a) Relative movement of the device 10 and the wire 14 to be processed in its longitudinal direction, so that a relative movement of the wire 14 through the center of the slide arrangement 34 takes place, and b) stopping the relative movement - e.g. by moving the device 15 with the wire 14 - and c) rotating the cam disk 38 to drive the slides 52.1-52.8 to scrape off the insulation; and Repeat steps a) to c) to strip the wire 14 at another length section 18.

[0070] Thus, the endless hairpin wire can be stripped in just one stop. For example, a cycle time of only about one second can be achieved, of which approximately 0.4 seconds are required for stripping and 0.6 seconds for moving the device to the next stripping point. The device 16 requires only a single servo motor (or other suitable type of cam drive 38).

[0071] The following is an exemplary construction of the counter bearing slide 58 based on the illustration in the Fig. 12 , 14 and 15 explained in more detail. The front end of the counter-bearing slide 58, directed towards the wire 14, is shown therein with the counter-holder 78.

[0072] The counter-holder 78 has a counter-holder plate 80 and guide jaws 82 attached to it, which pre-position the wire 14 for the cutting edge 60. As can be seen in particular from Fig. 15 As can be seen, the counter-support plate 80 is defined in its height h such that it corresponds to the desired minimum dimension of the stripped wire 14 (in the direction transverse to the direction of movement of the counter-support slide 58 and transverse to the wire movement direction 26) minus twice the width of a cutting gap 84 (approx. 0.05 mm to 0.1 mm). Fig. 15Figure 1 also shows a first and second knife 86.1, 86.2 of a knife set 88 of the cutting slide 56, the distance between which is set to the desired minimum dimension of the stripped wire 14.

[0073] The following is an example of the construction of the cutting slide 56 based on the illustration in the Fig. 12 and 15 to 24 explained in more detail. This shows Fig. 12 the mutually directed front ends of the cutting slide 56 and the associated counter-bearing slide 58 of one of the slide pairs 52.1-52.4, here for example the third slide pair 52.3, wherein the slides 56, 58 are in the basic position at a distance from the wire 14. Fig. 15 shows a detail of the front ends of the cutting slide 56 and counter bearing slide 58 in the engagement position. Fig. 16 shows a perspective view of the front end of the cutting slide 56 with the cutting edge 60. Figs. 17 and 18Two views show one of the knives 86.1, 86.2 of the knife set 88 of the cutting edge 60. Fig. 19 shows the knife set 88, adjusted to the appropriate distance. Figs. 20 to 24 The arrangement of guide elements 90 and an ejection element 92 in the cutting edge 60 is illustrated.

[0074] As can be seen from these illustrations, the cutting edge 60 has a first knife 86.1 designed as a carbide knife, a second knife 86.2 designed as a carbide knife, a first and a second guide plate 90.1, 90.2 as guide elements 90 assigned to the first and second knife 86.1, 86.2 respectively, a spring-loaded ejector as ejection element 92 and a first and a second retaining plate 94.1, 94.2.

[0075] How to get the Figs. 17 and 18 As can be seen, each knife 86.1, 86.2 is a flat carbide plate with a pointed shape. The tip is chamfered, thus forming a wedge angle of 96°. As in Fig. 19As shown, the first and second knives 86.1, 86.2 are combined with a tuning disc 98 to form a knife set 88. The height h1 of the tuning disc 98 determines the cutting dimension, which results in the desired wire dimension mentioned above after stripping.

[0076] It will now be referred to as Figs. 20 and 21 Reference is made to the respective guide element 90, e.g. designed as a guide plate 90.1, encloses the associated knife 86.1 of the knife set 88 with a U-shape and determines the penetration depth of the knife 86.1 into the wire 14 by means of a defined height offset h2 to the knife 86.1.

[0077] How to get the Figs. 22 to 24Between the matched knives 86.1, 86.2 and the guide elements 90, designed, for example, as guide plates 90.1, 90.2, there is an ejector, pre-tensioned into its ejection position by means of spring(s) 100, as an ejection element 92. The ejection element 92 is designed to push the wire 14 back out of the cutting edge 60 after stripping.

[0078] According to Fig. 24 The adjustment disc 98 between the blades 86.1 and 86.2 is adjusted to the required thickness to set the necessary cutting dimension (dimension of the wire after stripping). The maximum possible wire dimension before stripping is achieved via guide element adjustment discs 102 on the guide elements 90. Simultaneously, the same height difference should be ensured on both sides between the guide element 90 and the blades 86.1 and 86.2 to enable symmetrical material removal.

[0079] Once knives 86.1, 86.2 and guide elements 90 are correctly positioned, the counter-holder 78 and the cutting edge 60 are positioned as shown in the illustration. Fig. 15 aligned to each other by means of counter-holder tuning discs 104 in order to produce an equal cutting gap 84 between the knives 86.1, 86.2 and the counter-holder 78.

[0080] The following is a detailed embodiment of a stripping process as an embodiment of the programming of the control unit 22 for controlling the functions of the device and as an embodiment of the process.

[0081] The wire 14, for example, is positioned in the device 10 as a hairpin wire by a bending machine for producing hairpins, in which the device 10 is used. Such bending machines are known, for example, from [1] to [4]. The motion actuator drives the carriage 30 to move along with the wire 14. The servo motor of the cam drive 38 drives the belt drive 68 and thus the cam with the first and second beads 72.1, 72.2. The cam rollers 74 transmit the movement to the slides 52.1-52.8, which move linearly towards the center.

[0082] Due to the different design of the ridges 72.1, 72.2 on the cam disc 36, see Fig. 13The counter-position slide 58 with the counter-holder 78 precedes the cutting slide 56 with the cutting edge 60. Shortly before the counter-holder 78 reaches its final position in the center, the wire 14 is held in position with minimal play by the multiple, e.g., two, guide jaws 82. The counter-holder 78 remains in contact with the wire 14 in its final position until further notice.

[0083] The cutting slide 56 with the cutting edge 60 finally centers the wire 14 over its guide plates 90.1, 90.2, and the blades 86.1, 86.2 scrape off the insulating layer 12 (including some copper). The spring-loaded ejector – ejector element 90 – presses the wire 14 against the counter-holder 78 – for example, by compressing the spring 100. Due to the arrangement of the blades 86.1, 86.2, material is scraped off the wire 14 on both sides. The finished scraped wire 14 thus moves between the blades 86.1, 86.2, see [reference]. Fig. 10 , 11 and 15 .

[0084] Once the cutting edge 60 has reached its end position, it is immediately moved back to its starting position (radially outwards) via the contour of the first bead 72.1 and the cam rollers 74 arranged on the cutting slide 56.

[0085] The ejector element 90, designed here as a spring-loaded ejector, continues to press the wire 14 against the counter-holder 78; the spring 100 then relaxes. During the movement of the cutting edge 60, the ejector element 90 also pushes the wire 14 out of the blades 86.1, 86.2 to counteract any deformation of the wire 14.

[0086] Once the cutting edge 60 has been retracted far enough and the stripped wire 14 has been pushed out of the blades 86.1, 86.2, the counter-holder 78 moves into its home position. Now two sides of the wire have been stripped.

[0087] The aforementioned movement sequence is repeated on the other three of the four pairs of sliders (it is repeated three more times). Thus, all four sides and four radii of wire 14 are stripped to the previously defined width.

[0088] The following special feature occurs when stripping the radii of the wire 14. Due to the linear movement of the cutting edge 60, the radius on the wire becomes a chamfer in the copper after stripping. Fig. 26 Figure 1 shows a cross-section through the stripped length section 18 before stripping, and Figure 27 shows the same cross-section after stripping. The radii 108 become chamfers 110 after stripping.

[0089] Further possible embodiments: In some embodiments – not shown – the device is equipped only with the first and second slides 52.1, 52.2 and thus only has the first pair of slides 54.1 with only two slides, i.e., only a cutting slide 56 and a counter-bearing slide 58. This is possible for hairpin welding processes, since in principle it is sufficient for welding the wire ends arranged in a parallel butt joint during welding if only the longitudinal side – larger side surface 112 – of the wire 14, which lies against the other wire to be welded during the parallel butt joint welding process, is stripped (and, due to the selected symmetrical cutting edge design, also the other longitudinal side parallel to it).

[0090] Particularly in the configuration with only one pair of slides 54.1, the cam disk 36 can also be provided with only one control cam, which has the first indentation 76.1 on one circumferential area as part of the first control cam section 66.1 for controlling the cutting slide 56 and the second indentation 76.2 on the opposite circumferential area as part of the second control cam section 66.2 for controlling the counter-bearing slide 58. The correspondingly modified single control cam (bead) with the opposing first and second indentations 76.1, 76.2 is thus designed to drive both the movement of the cutting slide 56 and the movement of the counter-bearing slide 58. The correspondingly adapted cam disk 36 is then only rotated by up to 180 degrees and then rotated back again. In one variant, the first and second beads 72.1, 72.2 can also be modified.2. Each slider may extend only over a portion of the circumference; for example, they may extend over opposite halves of a circle. In other words, in the variant with fewer sliders, the part of the bulge 72.1, 72.2 opposite the respective indentation 76.1, 76.2 can also be omitted.

[0091] In other designs, instead of beads 72.1, 72.2, other designs with the control curves on the cam disc 36 are provided, e.g. grooves, slots, edges.

[0092] In other embodiments, the slider arrangement comprises only the first and second pairs of sliders 54.1, 54.2 with the first to fourth sliders 52.1-52.4 for stripping the longer wire ends and adjacent radii of the wire 14. It is also possible to provide three pairs of sliders 54.1, 54.2, 54.4, so that only two opposite ends of the wire and all corners are stripped.

[0093] As explained above, "single-stop machining" can refer to machining on a moving wire with a moving machining unit 16. Single-stop machining allows the machining to be performed by a single unit – unit 16 with the slide arrangement 34 – instead of, for example, using several independent units that perform the machining individually and then sequentially.

[0094] In other embodiments, the device 16 can also be stationary, and the movement mechanism 20 can also be omitted. In these embodiments, the wire 14 is stopped during stripping in order to perform the rotation of the cam disk 36 for stripping.

[0095] Instead of one or more of the tuning discs 98, 102, 104, other spacers may also be provided for adjusting and setting the corresponding distance.

[0096] In order to enable process-reliable stripping of wires for the production of coil windings in large-scale industrial series production with fast cycle times and high quality, a device (10) for removing an insulating layer (12) on a length section (18) of a wire (14) for forming a coil winding of an electrical machine has been described, comprising: a wire guide (24) for guiding the wire (14) to be processed through it in a wire movement direction (26); a slide arrangement (34) with several slides (52.1-52.8), which are arranged around the wire (14) to be guided through the wire guide (24) and are radially displaceable back and forth relative to the wire (14) guided in the wire guide (24), wherein at least one cutting slide (56) with a cutting edge (60) for scraping off the insulation (12) and at least one counter-bearing slide (58) for holding the wire (14) during scraping are provided such that a cutting slide (56) and a counter-bearing slide (58) are opposite each other and are movable towards and away from each other, and a cam disk (36) with a recess or opening (62) through which the wire (14) can be guided by means of the wire guide (24), wherein the cam disk (36) is rotatable by means of a cam disk drive (38) and has a first control cam area (66) that is at least partially annular in shape.1) for controlling and / or driving the movement of the at least one cutting slide (56) and a second at least partially annular control cam section (66.2) for controlling and / or driving the movement of the at least one counter-bearing slide (58).

[0097] Furthermore, a method for removing an insulating layer (12) on a length section (18) of a wire (14) for forming a coil winding of an electrical machine has been described, comprising: Providing a device (10) of the type mentioned above, and performing the following steps in a stepwise manner: a) moving the device (10) and the wire (14) to be processed relative to each other in its longitudinal direction, so that a relative movement of the wire (14) occurs through the center of the slide arrangement (34), and b) stopping the relative movement, and c) rotating the cam disk (36) to drive the slides (52.1-52.8) to scrape off the insulation (12); and repeating steps a) to c) to strip the insulation from the wire (14) at another length section (18). Reference symbol list:

[0098] 10 Device 12 Insulating layer (electrical insulation) 14 Wire (conductor) 16 Device 18 Length section 20 Movement mechanism 22 Control unit 22a Processor 22b Memory (with computer program stored therein) 24 Wire guide 26 Wire movement direction 28 Machine frame 30 Carriage 32 Motion actuator 34 Slide assembly 36 Cam disc 38 Cam disc drive 40 Wire guide unit 42 Base frame 44 Base 46 Mounting plate 48 Guide tube 50 Extraction tube 52.1 First slide 52.2 Second slide 52.3 Third slide 52.4 Fourth slide 52.5 Fifth slide 52.6 Sixth slide 52.7 Seventh slide 52.8 Eighth slide 54.1 First pair of Slides 54.2 second pair of slides 54.3 third pair of slides 54.4 fourth pair of slides 56 cutting slide 58 counter bearing slide 60 cutting edge 62 center opening 64.1 first control cam 64.2 second control cam 66.1 first control cam section 66.2 Second cam section 68 Belt drive 68a Timing belt pulley 68b Timing belt 68c Timing belt pulley section 72 Bead 74 Cam roller 76.1 First indentation 76.2 Second indentation 78 Counter holder 80 Counter holder plate 82 Guide pliers 84 Cutting gap 86.1 First blade 86.2 Second blade 88 Blade set 90 Guide element 90.1 First guide plate 90.2 Second guide plate 92 Ejection element 94.1 First retaining plate 94.2 Second retaining plate 96 Wedge angle 98 Tuning disc 100 Spring 102 Guide element tuning disc 104 Counter holder tuning disc 108 Radius on wire edges 110 Chamfers on corner edges of stripped length section 112 larger side surface 114 corner edges adjoining the larger side surfaces in one circumferential direction (e.g. clockwise) 116 smaller side surface 118 in the other circumferential direction (e.g.counterclockwise) corner edges adjoining the larger side surfaces hHeight of counter bearing plate h1Height of tuning disc (=desired wire dimension on the stripped length section) h2Height offset (determines penetration depth of the knife into wire.

Claims

1. Apparatus (10) for removing an insulating layer (12) on a length section (18) of wire (14) for forming a coil winding of an electrical machine, the apparatus comprising: a wire guide (24) for guiding through the wire (14) to be processed in a wire moving direction (26); a slider arrangement (34) having a plurality of sliders (52.1-52. 8) which are arranged around the wire (14) to be guided through the wire guide (24) and can be displaced radially back and forth relative to the wire (14) guided in the wire guide (24), wherein at least one cutting slider (56) with a cutting edge (60) for scraping the insulation (12) and at least one counter bearing slider (58) for holding the wire (14) during scraping are provided in such a way that in each case a cutting slider (56) and a counter bearing slider (58) are opposite one another and can be moved towards and away from one another, and a cam disk (36) with a recess or opening (62) through which the wire (14) can be guided by means of the wire guide (24), the cam disk (36) being rotatable by a cam disk drive (38) and having a first at least partially annularly revolving control cam portion (66. 1) for controlling and / or driving the movement of the at least one cutting slider (56) and a second at least partially annularly revolving control cam portion (66.2) for controlling and / or driving the movement of the at least one counter bearing slider (58).

2. Apparatus (10) according to claim 1, characterized in that the slider arrangement (34) comprises at least two of the cutting sliders (56) and at least two of the counter bearing sliders (58).

3. Apparatus (10) according to any one of the preceding claims, characterized in that 3.1 the first and second control cam portions (66.1, 66.2) are different portions of a common at least partially or completely annularly revolving control cam; or 3.2 the first control cam portion (66.1) and the second control cam portion (66.2) are formed on axially or radially spaced different control cams (64.1, 64.2); or 3.3 the first control cam portion (66.1) is formed by a first annularly revolving control cam (64.1) for controlling and / or driving the movement of several or all cutting sliders (56) and the second control cam portion (66.2) is formed by a second annularly revolving control cam (64.1) for controlling and / or driving the movement of several or all counter bearing sliders (58).

4. Apparatus (10) according to any one of the preceding claims, characterized in that 4.1 the cam disk is rotationally driven by means of a servo drive as a cam disk drive controlled by an electronic control unit; 4.2 the cam disk (36) is connected to the cam disk drive (38) by means of an endless traction drive, in particular a belt drive (68).

5. Apparatus (10) according to any one of the preceding claims, characterized in that the control cam portions (66.1, 66.2) or control cams (64.1, 64.2) are designed as axially projecting beads (72.1, 72.2), the sliders (52.1-52.8) having pairs of cam follower elements, in particular pins or cam rollers (74), which receive the associated bead (72.1, 72.2) between them.

6. Apparatus (10) according to any one of the preceding claims, characterized in that the slider arrangement (34) 6.1 has sliders (52.1-52.8) arranged evenly in a circle around the center in which the wire (14) is guided; 6.2 has first to fourth sliders (52.1-52.4); 6.3 has first to eighth sliders (52.1-52.8); and / or 6.4 has several pairs (54.1-54.4) of radially opposite sliders (52.1-52.8) comprising a cutting slider (56) and a counter-holder slider (58); and / or 6.5 is designed for cyclical co-movement with the wire (14).

7. Apparatus (10) according to any one of the preceding claims, characterized in that the cutting slider or sliders (56) each have a blade set (88) with a plurality of blades (86.1, 86.2) which are designed to scrape the insulation (12) on opposite sides of the wire (14).

8. Apparatus (10) according to claim 7, characterized in that the at least one cutting slider (56) 8.1 has one guide element (90, 90.1, 90.2) per blade (86.1, 86.2) which is guided in each case in a leading manner around a blade edge of the blade (86.1, 86.2) and has a height offset relative to the blade (86.1, 86.2) by means of which the penetration depth of the blade (86.1, 86.2) into the wire (14) can be determined; and / or 8.2 has an ejector element (90) which is elastically pre-loaded into an ejection position to support ejection of the wire (14) from the blade set (88); and / or 8.3 has a shim (98) between the blades (86.1, 86.2) for adjusting the distance between the blades.

9. Apparatus (10) according to claim 7 or 8, characterized in that the blade set (88) 9.1 has a first and a second blade (86.1, 86.2); and / or 9.2 has blades (86.1, 86.2) which are each formed from a hard metal plate having a pointed shape; and / or 9.3 has blade cutting edges on the blades (86.1, 86.2), the tip of which is chamfered to form a wedge angle (96).

10. Apparatus (10) according to any one of the preceding claims, characterized in that the counter bearing slider(s) (58) each have 10.1 a counter bearing element (80) for abutment against the wire (14) and / or 10.2 guide tongs (82) for pre-positioning the wire (14).

11. Apparatus (10) according to any one of the preceding claims, characterized by an electronic control unit (22) which is designed to control the device (10) to perform the steps in cycles: a) relatively moving the device (10) and the wire (14) to be processed in the longitudinal direction thereof, so that a relative movement of the wire (14) through the center of the slider arrangement (34) takes place, and b) stopping the relative movement and c) rotating the cam disk (36) to drive the sliders (52.1-52.8) to scrape the insulation (12); and repeating steps a) to c) to strip the wire (14) at another length section (18).

12. Apparatus (10) according to claim 11, characterized in that the control unit (22) is designed to control the device (10) when performing step c) for rotating the cam disk (36) with at least one complete revolution to successively drive the sliders (52.1-52.8) to scrape the insulation (12).

13. Method of removing an insulating layer (12) on a length section (18) of wire (14) for forming a coil winding of an electrical machine, the method comprising: providing an apparatus (10) according to any one of the preceding claims and performing the steps in cycles: a) relatively moving the device (10) and the wire (14) to be processed in the longitudinal direction thereof, so that a relative movement of the wire (14) through the center of the slider arrangement (34) takes place, and b) stopping the relative movement and c) rotating the cam disk (36) to drive the sliders (52.1-52.8) to scrape the insulation (12); and repeating steps a) to c) to strip the wire (14) at another length section (18).

14. Method according to claim 13, wherein an apparatus (10) with at least two cutting sliders (56) and at least two counter bearing sliders (58) is provided, wherein step b) comprises: rotating the cam disk (36) at least one complete revolution to successively drive the sliders (52.1-52.8) to scrape the insulation (12).

15. Computer program comprising instructions causing the device (10) according to any one of claims 1 to 12 to perform the method steps according to claim 13 or 14.