The present invention relates to an arrangement for marking a laminated rotor or stator package of an electric drive, produced in a progressive blanking tool, by means of a package arresting device and having the purpose of defining the tool, the manufacturer and, in the case of multi-row progressive blanking tools, the row of the tool used in producing the package, wherein the marking may also represent a combination of the foregoing marking purposes. The term progressive blanking tool as used throughout this document, refers to a tool arrangement which, in addition, enables the individual laminations to be joined together.

The mechanical joining of laminations to form a laminated package pole is provided in a conventional manner by means of mechanical clamps, the production of which in some of the preceding stations is likewise a part of the progressive blanking tool.

The invention relates to a design and an embodiment of particular elements of the tool which, combined with other customary structural and functional features of the progressive blanking tool, allow the aforesaid, package marking to be created at a substantially lower cost of producing the progressive blanking tool than with previously known technical methods.

From the viewpoint of the active components of the electric drive, the rotor and the stator, the rotating and the immobile stationary part of the electric drive, respectively, the subject of the invention relates to the production of rotor and stator laminated packages alike, fabricated in a progressive blanking tool from electric sheet of diverse quality and thickness. The individual laminations, which are the basic building components of rotor and stator packages alike, are joined together by mechanical connections, known as clamps, disposed in convenient or allowable locations on the individual laminas .

To simplify the disclosure of the invention and make it more readily apparent, just the term laminated package is used in the continuation, which in all instances and descriptions, however, is intended as encompassing the technological process of producing either a stator laminated package or a rotor laminated package.

Prior Art

There are presently two known techniques for marking a laminated package in a progressive blanking tool:

1. Integrating the shape of the laminated package marking in the contour of the cutting elements. When this arrangement is used, the laminated package marking takes shape already as the individual lamination is punched out in the blanking die. Albeit this configuration fulfills the marking requirement as such, it does mean that, particularly in the case of multi-row progressive tools, each individual final station has to be structured differently, that is: it must have a different geometry - comprising the different shapes which define a particular marking. Due to the differences between the individual tool rows, this is a substantially more expensive configuration, which is reflected particularly in the maintenance costs of the tool during its service life, or its operation, because all the different interchangeable types of spare parts appearing in the tool must be kept in stock. The same fact also poses a considerable organizational and logistical problem when planning for the necessary stock of tool spare parts .

Mechanically marking the surface of the material that the end products are made from beforehand, by means of appropriate writing implements, which are physically located such as to mark each row in the progressive blanking machine with a different color. This method of marking has proved unreliable because of the inherent possibility of the marking being lost due to a mechanical failure of the writing instrument, or to the color definition used being hard for the end customer to determine. With time, a given color may change hue, possibly leading to confusion or to recognition problems. Said difficulties may also arise from changes in the marking brought about by the use of additional technology, such as the use of a cooling and lubricating emulsion for the material being blanked. When the said emulsion comes into contact with the marking made by the writing implement, a chemical reaction may ensue and alter the marking. Background of the Invention

The progressive blanking tool according to Figure 2 is a known embodiment of a stamping tool, wherein various shapes are punched out from an individual lamina or product in separate stages or stations. Each one of said stations may represent one or several operations or shapes required by or included in the product. During operation, the material/strip 6, is advanced by one station 17, 18 with every stroke of the stamping press. Due to additional requirements posed by the design and the implementation of the tool - such as dimensioning maximum-sized cutting elements for increased intrinsic rigidity, facilitating the advancement of the strip, or simplifying the design as such - there may be present in the tool a number of idle/empty stations 18, that is, stations where no shapes are punched out in the product.

The above-said distance traveled by the strip between the individual strokes of the press is called the shift or step 16 and is quantitatively equal to the distance between the individual stations in the tool. In the tool design phase, care is taken to optimize the width 15 of the material used to a value ensuring a minimized gross consumption for a particular end product, while despite pursuing minimized consumption still not compromising those functions of the tool which could potentially, in a worst-case scenario, result in the operation of the device being flawed, or even in the end product being defective. The material not representing a specific functional shape or area in the end product is called scrap and is punched out successively at the individual stations. Individual portions thereof are removed in a downward direction through the apertures in the die elements 7, with each stroke of the punches 3 through the material 6, dropping out from the bottom portion of the tool in the end. The punches 3 are secured in the upper portion of the tool, comprising the upper yoke of the tool 1 and the guide plate with inserts 4, having the function of guiding, or rather, positioning the punches 3 relative to the lower portion of the tool 13. Into the punches for punching out portions of the lamina 3, impressing punches 2 are inserted, as supports for impressing the previously formed clamps - that is, the connecting elements joining the laminas together. As the individual products/laminas 19 leave the die elements 7, they are led directly into the package arresting device, which is dimensioned such that its outer dimension is smaller than the dimension of the product. The package arresting device is arranged directly below the die element 7 for blanking free the outer contour of the individual product/lamina 19. This gives rise to a braking effect in the arresting device, generating an upwardly directed reaction force, which allows the impressing/entering of the connecting element ( s ) /clamps 5 into the previously blanked lamination to occur. The impressing force of the clamps 5 is exerted from above, as the action of the ram, or upper portion of the press, and by cyclically repeating this operation a package of a predetermined height is obtained, all the component parts thereof being thus interlocked by means of the clamps 5. After falling out from the package arresting device, they are evacuated from under the tool/press in various ways. The previously punched^-out shapes are still connected together in the strip and will form the end product only after final blanking out.

The configuration of the tool may be such that after the final blanking out there remains no web, or scrap strip, or a so-called scrap strip may remain, which keeps the individual previous stampings together till the final blanking free of the product and is cut out into smaller pieces at the output of the tool after the final blanking free, said scrap strip pieces as such representing scrap.

Description of the Invention

According to the invention, the task at hand is solved with a design of the package arresting device wherein a predetermined portion of the contour of the arresting element comprises a marking ridge, which draws the desired marking or a combination of markings while the product is passing through the arresting device, the design of the blanking elements for blanking out the shape of the outer contour of the product being such that in the case of a multi-row progressive blanking tool they are all perfectly identical to one another.

The invention shall be described according to an embodiment of a laminated pole of a stator package for an electric drive. The entire stator, after winding the individual poles, consists of a given number of poles, depending on the geometry, or rather, on the intended application of the electric drive as such. The invention is applicable to various types of blanked products, such as stator packages, rotor packages, stator pole packages, rotor pole packages, core packages, as well as to all the foregoing applications when instead of a package, individual laminations are blanked out.

The invention is expounded by means of the appended drawings, representing:

Figure la: a lamination from a 3-row progressive stamping tool with one marking;

Figure lb: a lamination from a 3-row progressive stamping tool with two markings;

Figure lc: a lamination from a 3-row progressive stamping tool with three markings;

Figure 2: three examples of a lamination marking from a 3- row progressive stamping tool, in top view on the strip from the tool;

Figure 3: a longitudinal cross-section of the final station in a progressive stamping tool;

Figure 4: enlarged detail view of the shape of the marking on lamination 19a - first row in the tool;

Figure 5: enlarged detail view of the shape of the marking on lamination 19b - second row in the tool;

Figure 6: enlarged detail view of the shape of the marking on lamination 19c - third row in the tool.

With reference to the drawings, an embodiment with a 3-row progressive stamping tool is disclosed. As already described, the die elements 7 for blanking out the outer contour of the lamination 19 are fabricated with a mutually identical geometry, without any marking shape integrated into the contour as such. The arresting system of the package is composed of the arresting device support 12 and an adequate number of arresting elements 11, which are inserted into the arresting device support 12 and generate, as explained previously, the force enabling the laminas to be joined together. According to the predefined manner of package marking, the shape, or rather the ridged profile 10, projecting into the outer profile of the product by a certain amount, or depth, is added to the shape of a given number of arresting elements 11, so that, when the package passes through the arresting device, the said ridge draws a groove-shaped line or a plurality of such lines onto the product, that is, onto the lamination package, so that a desired package marking 20 is created, which is used for identifying or tracing the product later on. The ridged profile 10 has the shape of a lug projecting from the arresting element in the direction of the product, namely the lamination 19. The ridge element 10 projects out of the arresting element 11 by 0.05 to 0.1 mm.

The arresting element 11 with its ridged profile 10 performs two functions - with the part of its surface which is in contact with the product, it still generates the force required for mutually joining together the individual laminations, while with its ridged profile 10 drawing on the surface of the product the marking 20, shaped as a deformation of the edge of the lamination.

According to Figure 2, depicting embodiments of a lamination marking from a 3-way progressive blanking tool in top view on the strip, lamination 19a, fashioned in the first row, has one marking, lamination 19b has two markings, and lamination 19c has three markings.

Pictures 3, 4, 5 and 6 illustrate an embodiment of the aforesaid 3-way progressive blanking tool, wherein the marking insert, that is, the ridged profile 10 of the arresting elements, is shown as having different numbers of marking ridges, depending, on the row in the tool it is intended for.

Marking packages by means of the arresting device, in other words, marking a laminated rotor or stator package of an electric drive, produced in a progressive blanking tool with the purpose of defining the tool, the manufacturer and, in the case of multi-row progressive blanking tools, the row of the tool used in producing the package, as embodied herein, is therefore characterized in that the arresting elements 11, inserted into the arresting device support 12, generate the force which enables the laminations to be joined together, at least one ridged profile 10 being fashioned on at least one arresting element 11.

The manner of marking disclosed herein may be utilized or applied in products of the most various shapes, with the only condition that part of the arresting surface comprises a marking ridge, even if the arresting device is implemented as one single piece, or if it presents single arresting inserts/elements inserted into the arresting device support, the latter embodiment having the advantage of being adjustable and substantially cheaper to manufacture/implement. The embodiment is likewise applicable to the production of both rotor and stator laminated packages, as well as to all other applications of progressive stamping tools, which are essentially intended for manufacturing individual laminations, as well as packages, whose component parts are joined together with clamps to form a package for a given application.