Method of manufacturing layered stack, layered stack, and electric machine

Abstract

To provide requirement conditions for effectively producing a layered stack (a stator package, a rotator package and the like) in a production environment.SOLUTION: A method for manufacturing a layered stack comprises: a step A) of providing a metal sheet (1) having an adhesive coating; a step B) of transporting the metal sheet into a serial molding system including cutting means (4), separation means (6), and activation means (5, 5a, and 5b); a step C) of cutting a molding component (2) with the cutting means (4); a step D) of activating the adhesive coating; a step E) of separating the molding component (2); a step F) of positioning the molding component (2); and a step G) of repeating the steps C) to F). In order to provide a target fracture point for separating molding component stacks (3 and 3'), a treatment liquid is supplied to the adhesive coating of some molding component (8) by a treatment device (9).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminated stack. The present invention also relates to a stack section and an electromechanical device of the laminated stack.

Background Art

[0002] The operating modes of various electromechanical devices, particularly electric motors, have been known for a long time. The importance of electric motors is increasing ever more because of the increasing use of electric motors in personal passenger transportation, also referred to by the buzzword "electromobility". The main components of all electric motors include a stator and a rotor, where the stator means the stationary part of the motor and the rotor means the movable part of the motor.

[0003] One problem in providing an electric motor is to improve the efficiency of the electric motor, such as the power output per unit volume and / or efficiency, as part of an effort that makes economic sense.

[0004] One idea for providing an efficient electric motor is the manufacture of the stator and / or rotor, or the components of the stator and / or rotor as so-called stator packages or rotor packages. Other components to be manufactured are pole cores or pole segments. In this case, the aforementioned components are assembled from individual so-called lamellas as a laminated stack, also called a plate stack. The term "lamella" means a shaped part taken from an electromagnetic steel sheet or strip, for example by punching. The plate stack is composed of a large number of thin lamellas stacked on top of each other, and these lamellas are electrically insulated from each other, at least partially or preferably completely. For such purposes, it is actually known to use so-called electrical insulation coatings, which are classified, for example, into so-called insulation classes.

[0005] The manufacture of such a stacked stack always includes a step of manufacturing the lamellae and a step of interconnecting the lamellae. Preferably, the connection is achieved in such a way that the individual lamellae are partially or preferably completely electrically insulated after the connection. This preferably means that two adjacent lamellae are not galvanically interconnected.

[0006] The individual lamellae can be manufactured, for example, by punching. The connection of the punched lamellae to form a stacked stack can be achieved by various known methods, such as bolting, application of clips, welding, or punched stacking. However, due to the mechanical effects occurring during the connection process, in each of these manufacturing methods known to those skilled in the art, there is an accompanying negative impact on the electromagnetic properties of the resulting stacked stack finished product after the connection. In particular, the inevitable mechanical stress in the connections manufactured according to the prior art can, to at least some extent, adversely affect the magnetic properties and the shape of the magnetic field lines within the stacked stack. This can, for example, directly adversely affect the efficiency of the electric motor manufactured therefrom. The electrical connection between two or more lamellae occurring in connection processes such as punched stacking or welding results in additional losses.

[0007] An excellent option for reducing the adverse effects on the lamellae due to mechanical effects and at the same time achieving good insulation between the lamellae is to use an adhesive as the connecting means. In many cases, a suitable adhesive system has insulation properties similar to those of an electrically insulating coating.

[0008] Procedures known to those skilled in the art involve the use of so-called baking paints. For example, the use of baking paints for bonding punched electromagnetic steel sheets is described in German Patent No. 3829068. One procedure for using baking paints involves coating a metal sheet (especially a metal sheet strip), subsequently punching individual lamellas from the metal sheet, aligning the individual lamellas, and then heat-treating the resulting laminated stack at a defined period and temperature. In many cases, the lamellas are pressed against each other during the heat treatment. For example, pressing is carried out by applying an axial force (preferably a uniform surface force) to the laminated stack with respect to the end faces and directing the force towards the interior of the laminated stack. Typical reaction temperatures are between 150°C and 250°C, and the typical time for the baking paint to react is between 30 minutes and 150 minutes, followed by a cooling phase. However, since, for example, the core temperature set for the component affects the course of the baking process, the exact parameters inherently depend on the specific baking paint used and the specific geometric shape present. Excellent electromagnetic properties of the stator package and / or rotor package can generally be achieved by this procedure. However, due to the time-consuming procedure, it immediately becomes apparent that the use of baking paints is not suitable for continuous mass production or at least not optimal.

Summary of the Invention

Problems to be Solved by the Invention

[0009] Against the background of the above assembly, the object of the present invention is to create the necessary conditions for efficiently producing a laminated stack, i.e., especially a stator package or a rotor package, in a production environment.

[0010] Furthermore, apart from the desire for further efficiency improvement, the object of the present invention is to provide electromagnetic components and electromechanical devices with improved conversion of electromagnetic energy to mechanical energy or vice versa.

Means for Solving the Problems

[0011] This object is achieved by the method according to claim 1, the stack section of the laminated stack according to claim 16, and the electromechanical device according to claim 17.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2a

Figure 2b

Figure 3

Embodiments for Carrying Out the Invention

[0013] The method of the present invention for manufacturing a laminated stack for an electromechanical device includes at least the following steps. A) Providing a metal sheet with an adhesive coating that is at least partially curable. This means that the metal sheet has an adhesive coating that cures after activation (for example, heat-induced activation) to embody adhesive properties. The adhesive coating is a polymer-based adhesive coating. The metal sheet is preferably coated with the adhesive coating on either the entire surface of one side or, particularly preferably, the entire surface of both sides. The metal sheet may be an electromagnetic steel strip or a plate cut out from a metal sheet strip. B) Conveying the metal sheet into a series system. The series system has at least a cutting means, a separating means, and an activation means for activating the adhesive coating. Preferably, the activation means is arranged between the cutting means and the separating means.

[0014] The term "in-line system" means that a number of processing stations, i.e., at least the above-mentioned processing stations, are arranged in a predetermined order, and a metal sheet (for example, an electromagnetic steel strip) supplied to the in-line system is automatically and sequentially processed at predetermined stations.

[0015] Cutting means are used to form the structure of the lamellae to be produced. This can be done, for example, in a plurality of steps with one cutting means or in a plurality of steps with different cutting means. In this case, in any case, it is preferable to perform a multi-stage structuring from the inside to the outside of the lamellae. That is, a number of cutting steps that require a plurality of cuts are preferably provided such that the cutting steps first form the innermost structure of the lamellae and then gradually cut towards the outside of the lamellae.

[0016] The cutting means can be designed, for example, as a punching machine. In this case, the cutting in step C) becomes a punching step.

[0017] Also, the cutting means can be in the form of a laser. In this case, the cutting in step C) becomes a laser beam cutting step.

[0018] The in-line system can also have a sequence of a plurality of cutting means, and can be designed, for example, as a punching tool having a plurality of punching stages arranged in sequence, or can be designed as a sequence of a punching tool and a laser. Preferably, at least one cutting means can be designed as a progressive type that punches the intended shape of the laminate into the electromagnetic steel strip from the inside to the outside of the lamellae.

[0019] In the above context, the term "lamella" refers to a shaped article obtained by cutting out from a metal sheet, in particular, a shaped article obtained by punching.

[0020] The activator for activating the adhesive film can introduce heat into the adhesive film, and in principle, the input of heat can be generated by any method. In particular, the activation means can have a means for emitting infrared rays, for example, a NIR radiation source, that is, a light source designed to emit electromagnetic radiation within the NIR wavelength spectrum (that is, wavelengths between 400 nm and 10 μm, preferably between 780 nm and 3 μm).

[0021] Alternatively or additionally, the activation means can include induction heating for heating the adhesive film, and in particular can include an induction coil.

[0022] Furthermore, as described above, the in-line system has separation means. This separation means is preferably in the form of a cutting die that uses a force perpendicular to the surface of the metal sheet, and sequentially separates the lamellas by cutting the lamellas from the metal sheet including the outside of the lamellas, and, preferably in the same processing step, transports the lamellas to a receiving device in which the lamellas are collected and disposed under the metal sheet. The cutting die preferably punches out the outer boundary of the lamellas from the metal sheet. Since punching and extrusion have the advantage of being highly synchronized, it is preferable that the cutting means and the separation means are part of the same press.

[0023] C) Using cutting means, in one or more steps, cut out a shaped part from the metal sheet provided in step A. For example, the shaped part is a rotor lamina or a stator lamina. In the in-line system, using cutting means, cut out from the metal sheet provided in step A preferably an electrical component whose outer contour has not yet been formed (in particular a shaped part designed as a stator lamina or a rotor lamina). The outer contour is only formed in step E. In this case, following step C, the shaped part has all contours other than its outer contour. Alternatively, an embodiment can also be provided in which the cutting out of the shaped part also includes the cutting out of the outer contour.

[0024] D) Activation of the adhesive film of the formed part by an activator for activating the adhesive film, preferably activation of the entire area of the adhesive film. The formed part formed in step C is preferably activated. That is, the activation in step D is performed after the cutting in step C. By activating the adhesive film by heat input, the punched formed part can form (i.e., be preliminarily fixed) an adhesive bond. The term "preliminary fixing" means that the formed part has sufficient elasticity for further processing but is not fixed enough for industrial use of the laminated stack finished product. The adhesive bond can be at least partially chemically cured and its final strength can be improved at a later stage of the process by post-consolidation under pressure and / or temperature in the latter half of the process.

[0025] In a particular embodiment, the activation temperature in a series system can be between 30 °C and 180 °C, preferably between 40 °C and 120 °C, particularly preferably between 50 °C and 100 °C.

[0026] E) Separation of the formed part using a separating means and, as step F, placement of the formed part within a positioning area for constructing a stack of formed parts, preferably guiding beyond its outer shape. The positioning area serves to place the formed part in a positionally and / or angularly aligned state on another formed part already present in the positioning area. As a result, a stack of formed parts that are aligned with each other and equipped with activated adhesive is finally obtained for each formed part in a sequentially increasing manner. The separation of the lamellae from the metal sheet by a separating means, preferably performed as punching, is preferably carried out in the same process step as the placement of the formed part in the positioning area, i.e., the separation in step E and the placement in step F (including the preferred adhesion of each lamella to the preceding lamella) are preferably carried out in the same process step. This includes guiding onto the stack of formed parts being formed and applying pressure by the separating means to the same stack if appropriate.

[0027] The positioning area can be, for example, a cylindrical tube that conforms to the outer shape of the molded product, such as a cylindrical tube in the case of a molded product inscribed in a circle, and the tube is located below the conveying surface of the molded product. The positioning of the molded product is performed through the positioning area, and is designed and provided, for example, as a cylindrical hollow tube having a cross-section substantially corresponding to the cross-section of the molded product, and is aligned therewith in the provided positioning. The positioning area can also correspond to an image of a lamella, and thus can contact the positioning area over the entire surface area.

[0028] G) Steps C) to F) are performed in the provided order, for example, in the order of step C) → step D) → step E) → step F), or steps C), D), E) and F) are performed in a combined order, and then repeated to continuously stack the molded parts stack. That is, the molded parts are continuously arranged in the positioning area. At this time, it is preferable to perform so that the positioning area is continuously and completely filled.

[0029] It is also possible to multi-columnize all the steps, that is, to punch out two or more lamellas from the electromagnetic steel strip in parallel and / or continuously (offset diagonally or rotated with respect to each other according to the number, shape and arrangement).

[0030] When the predetermined number of molded parts is reached, the next molded part is provided with the treatment liquid in at least some areas using a treatment device to reduce the effect (i.e., the adhesion strength) of the adhesive film (i.e., to make the adhesion strength smaller or no longer exist at all). The adhesive film at this position enables improved separability between the laminated part below the adhesive film with reduced effect and the laminated part above the adhesive film with reduced effect. This separability exists in the adhesive film, and therefore, the adhesive film is provided as a target breaking point that can easily separate the lamellas directly adjacent to the adhesive film from each other.

[0031] In other words, by continuously repeating steps C) to F), a treatment liquid is applied to at least a part of the selected molded parts using a processing device, reducing the effect (i.e., adhesive strength) of the adhesive film of these selected molded parts, and enabling easier separation of the stack section below the adhesive film with reduced effect from the stack section above the adhesive film with reduced effect. Select the molded parts as the selected molded parts, and while continuously continuing the process, select the resulting stack section (having a desired number of molded parts and thus a desired molded part height) so that it can be separated from the positioning device below the receiving side of the positioning device, thereby providing the stack section as a stacked stack.

[0032] In this way, the molded part stack is continuously formed, re-divided into stack sections, and in each case, one stack section is preferably continuously separated from the molded part stack as a stacked stack.

[0033] For example, for each molded part placed on the molded part stack on the top side of the positioning area, move the bottom side by the thickness of the molded part. And while replenishment is continuously being carried out on the top side, as soon as a complete stack section exists on the bottom side, it is immediately possible to separate the section and prepare it as a stacked stack.

[0034] In addition to the use of the treatment liquid, heating, i.e., the activator, can also be temporarily deactivated in the area where the treatment liquid is applied, preferably only during the handling of the selected molded parts.

[0035] The application of the treatment liquid to at least a part of the molded part is carried out before step F), preferably before step E), also preferably after step C), particularly preferably after step D), i.e., particularly preferably as an additional step between step D) and step E).

[0036] Preferably, the processing liquid is supplied to the entire surface of one side of the molded part. Alternatively, the processing liquid is also supplied to the entire surface of both sides of the molded part.

[0037] In one variant, the processing liquid is supplied to one surface of the molded part, i.e., the surface opposite the separating means. This provides the advantage that subsequent unintentional transfer of the processing liquid to the molded product by the separating means is avoided.

[0038] The number of arrivals can also specify multiple numbers of arrivals, and the reduction of the effect is achieved even after the arrival of the said number of arrivals. It should be understood that according to one or more specifications, the reduction of the effect can also be achieved multiple times before reaching the desired number of molded parts. Thereby, a stack of molded parts having at least one target breaking point, or, if multiple numbers of arrivals are specified, a stack of molded parts having multiple target breaking points is provided. At one or more target breaking points, the stack of molded parts can be divided into two or more stack sections, which is preferably done continuously during the ongoing process. The number of target breaking points of the stack of molded parts before separating the stacked stack depends only on the height of the stack section and the height of the positioning area.

[0039] The processing device is preferably arranged behind the activating means, i.e., the molded part first passes through the activating means, where the treatment of the adhesive film is carried out. Alternatively, the processing device is arranged after the cutting means and before the activating means.

[0040] In other words, the formed part stack is formed in the positioning area up to the intended total height and is prepared as a stacked stack (i.e., a stacked stack of a desired number of formed parts having one target breaking point or multiple target breaking points) when the total height is reached. Such a target breaking point is characterized in that the adhesive force between two adjacent formed parts is smaller than the adhesive force between two adjacent formed parts other than the target breaking point. The target breaking point is formed by reducing the effect of the adhesive (i.e., its possible adhesive force) after a predetermined number of formed parts as described above. Also, when forming the formed part stack in the positioning area, this can be repeated multiple times. For example, a formed part stack having a desired number N of formed parts can have a target breaking point after reaching N / n formed parts respectively, and the effect is that the effect of the adhesive film decreases for every N / n-th formed part. As a result, the formed part stack can have (n - 1) target breaking points and can be divided into n smaller stack sections. Here, N is a natural number divisible by the natural number n.

[0041] As in the above example, until the desired number of formed parts is reached, all of the successive planned number of formed parts reached have the same interval, and the desired number of formed parts can be separated into stack sections having the target breaking points evenly distributed and having the same height at the breaking points.

[0042] As an alternative, when it is required to form a stacked stack having target breaking points for separating a desired number of formed parts into stack sections having different heights from each other, the successive planned number of formed parts can be spaced apart from each other until the desired number of formed parts is reached.

[0043] The stack section is removed separately from the stack of molded parts. The stack section is separated, for example manually, in an adhesive film with reduced effect acting as a target breaking point based on the adhesive force still acting between two stack sections. The individual stack sections can then be used as a stacked stack finished product, for example as a stator finished product, as a rotor finished product, or as a finished product of a stator segment or rotor segment.

[0044] A special embodiment in which a metal sheet laminate is bonded to the entire surface has the advantage that an integral sealed cooling channel can be provided. This is particularly advantageous when using different or incompatible cooling media for a plurality of electrical components (for example, rotors and stators). The cooling channels can also be stamped into the lamellae or provided between the laminated stack and an adjacent component (for example, a shaft or housing).

[0045] The stator, and possibly also the rotor, can be composed of a plurality of segments.

[0046] Accordingly, in step G), it is provided that the target breaking point or a plurality of target breaking points are incorporated into the stack of molded parts filled throughout the positioning area, and the target breaking point or the target breaking points are generated by subjecting the molded parts at the target breaking point to an additional process during the course of steps C) to F). This additional process consists of providing a treatment liquid, at least partially and preferably over the entire surface, to the molded part located at the target breaking point in order to reduce the effect of the adhesive film of this molded part.

[0047] In one variant, the molded part coated with the treatment liquid can be provided with the treatment liquid on only one surface. This surface is located at the target breaking surface of the molded part.

[0048] In an alternative variant, the shaped part coated with the treatment liquid can be provided with the treatment liquid on both surfaces. In this case, the shaped part is located at two planned fracture surfaces, and the shaped part functions as a sacrificial lamella that is not part of the stack section.

[0049] The term "metal sheet" generally refers to a rolled product made of a metal material, and in addition to thin-gauge metal sheets or thick-gauge metal sheets, in particular, the sheet can also refer to a metal strip, for example, a metal strip or metal sheet made from a soft magnetic material, a steel strip or an electromagnetic steel strip. Optionally, other manufacturing methods of the metal sheet can also be used.

[0050] The laminated stack is preferably either a stator package or a rotor core. In addition to the adhesive, the laminated stack consists of so-called lamellas and can therefore also be called a laminated stack.

[0051] According to an advantageous development of the aforementioned method, the activation means has a first infrared irradiator. The first infrared irradiator is used to irradiate the adhesive film with infrared rays, thereby activating the adhesive film by the heat input.

[0052] In other words, by irradiating for a period between 0.05 seconds and 1 second at the emission output required to reach the activation temperature, a temperature sufficient for activation is brought about in the metal sheet, in particular in the adhesive. This temperature clearly depends on the exact choice of the adhesive and the properties of the shaped part (in particular the surface and the material) and can be easily determined by a person skilled in the art entrusted with the implementation of the present invention.

[0053] Particularly preferably, the activation means or the plurality of activation means are arranged between the cutting means and the separating means and have at least one upper infrared irradiator directed in the punching direction onto the surface of the first metal sheet. Alternatively, the activation means may be arranged at a position past the side of the metal sheet where the cutting means are arranged and include at least one lower infrared irradiator directed in the direction opposite to the punching direction. Alternatively, both at least one upper infrared irradiator and at least one lower infrared irradiator can be provided. The arrangement of the infrared irradiator with respect to the lamella surface does not necessarily have to be at a right angle and may be at different angles.

[0054] In particular, when there are upper and lower infrared irradiators, if an adhesive film is provided on both sides of the metal sheet used, the adhesive can be activated in a particularly suitable manner on both the first metal sheet side and the second metal sheet side on the opposite side, and an advantageous result can be obtained in that excellent adhesion between the metal sheets can be expected.

[0055] According to one development, the activation means has a second infrared irradiator. The first infrared irradiator and the second infrared irradiator emit infrared rays of different wavelengths and activate the adhesive film at different activation depths. For example, it is possible to arrange for the first infrared irradiator to emit infrared rays with a wavelength between 780 nm and 1200 nm and / or for the second infrared irradiator to emit infrared rays with a wavelength between 1200 nm and 3000 nm. Such an arrangement makes it possible to activate the adhesive film in a more uniform manner, particularly more continuously with respect to depth, due to the different penetration depths depending on the wavelength. This is accompanied by the advantages of particularly good adhesion and / or particularly good force absorption capacity.

[0056] Such an arrangement is sometimes also referred to as dual activation. To repeat, this dual activation can be carried out on one side or both sides.

[0057] Alternatively or additionally, the activation means can have an induction heater, and when the metal sheet is induction heated, the adhesive is activated starting from the adhesive surface of the metal sheet having the adhesive coating, so that there is an advantage that good activation of the adhesive and subsequent adhesive strength are achieved.

[0058] As a special development, for example by induction heating, the strip is preheated before entering the cutting means. This has the advantage that less heat is required for activation in the press, or the total amount of heat introduced increases, so that the adhesive meets higher requirements, for example with regard to mechanical properties.

[0059] Another advantage of the preheating is the reduction of the pressing force and the resulting well-known advantages, as well as the reduction of the deformation load and the introduction of internal stresses. This effect can be achieved particularly well when additional optional adjustments of cutting tools known to those skilled in the art are made.

[0060] As a further development, in order to maintain the heat introduced into the entire system as much as possible, performing some or many, preferably all, of steps B) to E) within the housing of the in-line system also has the advantage of higher energy efficiency of the entire process.

[0061] Furthermore, in the inlet of the strip and the post-compression station, the in-line system can be actively heated partially or as a whole. For this purpose, the generally used oil heating of the compression frame and tool holder is extended to include, for example, preferably a counterflow electric heating cartridge-equipped blower for tool, post-compression station and / or internal heating.

[0062] In a particular embodiment, the activation temperature in the series system can be 30°C to 180°C, preferably 40°C to 120°C, and particularly preferably 50°C to 100°C. In the post-compression station, post-compression can be carried out at a temperature higher than the activation temperature. In a further development, a variant is provided, according to which the processing device has an application unit, and using the application unit, as a treatment of the adhesive film, at least partially apply a treatment liquid applied to the adhesive film to the molded part. The treatment liquid serves to reduce the effect of the adhesive on the selected molded parts after the number of molded parts has reached the planned number. Thus, the resulting stack of molded parts has a kind of target breaking point at this time, whereby the two stack sections arranged one above the other can be separated. The application device can be, for example, an application roller or a roller unit consisting of two application rollers rotating in opposite directions, and the roller or roller unit travels parallel or perpendicular to the conveying direction of the molded parts in the series system in order to apply the selected molded parts.

[0063] The treatment liquid can be applied to one or both sides of the selected molded parts. When the treatment liquid is applied to both sides of the molded part, the molded part is separated from each stack section on both sides and can be removed as scrap having no further function.

[0064] Preferably, the treatment liquid is applied to the entire surface of the molded part.

[0065] Preferably, as the treatment liquid, punching oil is applied to the adhesive film. The advantage is that it is easily available, and in any case, punching oil is inevitably used in the process, so it is suitable because no undesirable reactions due to the use of another type of substance are expected. The punching oil is preferably a self-evaporating type punching oil. For example, a non-water-soluble coolant lubricant, particularly a medium-viscosity metalworking oil for preventing cutting, can be used as the punching oil.

[0066] For example, an oil that is suitable for deep drawing and can ensure a lubricating film that is uniform in terms of adhesiveness and wettability and does not contain heavy metals such as chlorine and barium can be used. The oil has a viscosity at 40°C of 80 to 110 mm 2 / s, preferably 90 to 100 mm 2 / s and more preferably has a flash point of 150°C or higher, preferably 170°C or higher. In particular, the oil preferably contains phenol and isopropyl phosphate, preferably in a ratio of 3:1, and optionally contains triphenyl phosphate in a ratio of 5% by weight. For example, an oil sold under the trade name Iloform FST 16 by Castrol at the filing date of the present application can be used.

[0067] Alternatively or additionally, an irradiator that overexposes the adhesive film can be used as a treatment for the adhesive film. For example, an infrared irradiator used for activation can be used for overexposure by simply increasing the beam output of the infrared irradiator to a selected molded part using, for example, a control system and / or increasing the residence time of the molded part under the infrared irradiator by temporarily decelerating or stopping the conveyance of the molded part.

[0068] Alternatively or additionally, a wetting unit can be used as a treatment for the adhesive film to apply a coolant (e.g., liquid nitrogen) to the adhesive film.

[0069] In step F), the molded parts are arranged by the method according to the invention, and they are also compressed using an axial force (i.e., a force directed in a direction perpendicular to the flat surface), for example, by a pressing ram, preferably after each molded part arrangement, or after the arrangement of a predetermined number of molded parts, or after the formation of a stack of molded parts. The axial force supports the force resulting from the inherent weight of the molded part but is significantly lower than the force applied during any post-compression.

[0070] Particularly preferably, after the stack section is separated, the stack section is post-compressed in a press by the pressure on the end face (i.e., the pressure perpendicular to the lamella surface), preferably by a pressure uniform over the entire end face. This is carried out at a pressure between 10000 N / (14000 mm 2 ) and 200000 N / (10000 mm 2 ), preferably between 50000 N / (14000 mm 2 ) and 150000 N / (10000 mm 2 ), and at a forming part stack temperature between 30 °C and 180 °C, preferably between 40 °C and 120 °C, particularly preferably between 50 °C and 100 °C. The compression is carried out in a two-stage process, where the first stage is the formation of the forming part stack in step F) or the formation of the stack section of the forming part stack in step F), and the second stage is the post-compression. Two-stage forming has been shown to result in a significant increase in adhesion, i.e., the force to be applied in a top-pull test to separate the stack sections is approximately doubled. A measurement example thereof is shown below. Other proven advantages include improved heat dissipation and an improvement of more than 5% in the shear strength of the entire composite material.

[0071] The exact matching of temperature and pressure should be carried out by a person skilled in the art taking into account cycle time and economic aspects. Also, the matching can depend on the ratio of the thickness of the adhesive to the thickness of the metal sheet and the selected configuration of the activation means, but in particular can also depend on the requirements of the part to be produced.

[0072] The temperature of the forming part stack is between 30 °C and 180 °C, preferably between 40 °C and 120 °C, particularly preferably between 50 °C and 100 °C. This temperature is preferably achieved by heating the forming part stack in a positioning device using an irradiator that generates heat. Alternatively, the irradiator may be arranged within or subsequent to the separating means, and / or an induction device may be used. In addition, it is preferable to utilize the waste heat generated from this heating in the aforementioned region for post-compression.

[0073] The compression step is carried out by compressing the stack in the axial direction of the stack, i.e., in a direction perpendicular to the surface of the lamellae, by means of a uniform surface pressure on the end faces. This compression results in a very good adhesive bond between the individual shaped parts, which contributes to the long service life of the stack. Preferably, the downstream compression step is carried out at a downstream compression station outside the press.

[0074] In a further development, the compression can also be carried out by displacement control instead of force control. This can be achieved, for example, by means of an adjustable stop. In combination with a very precise temperature control, the axial length of the part can be adjusted very precisely. However, alternatively, the compression step can also be carried out preferably using the pressure of a separating means, partially or completely.

[0075] The very good mechanical strength of the laminate achieved by adhesion and post-compression is particularly advantageous, so that, for example, machining can be carried out more easily and precisely. Thus, requirements that increase with speed or radial speed can also be carried out more easily. Another advantage is the high degree of design freedom.

[0076] For the uniform heating of the individual sheets (or sandwiches), a more homogeneous heating and the associated advantages (e.g., better geometric properties, lower internal stresses) are obtained.

[0077] Particularly preferably, this method is carried out using a metal sheet coated with an adhesive paint as an aqueous dispersion on the metal sheet. The advantage of the aqueous dispersion is that the paint system is free of organic solvents (VOC-free).

[0078] In addition, since the coated sheet dries to almost non-stickiness, there is also the advantage that individual windings can be wound into a coil without sticking to each other. Chemical cross-linking by subsequent pressing and heating is also possible. Solvent-based dissolved epoxy resin systems are generally not high molecular weight systems sufficient for drying to a non-sticky state, and individual windings in the coil have the drawback that they cannot be rewound without difficulty, if not at all, which hinders their use in subsequent processes.

[0079] Therefore, in a particularly preferred embodiment, one embodiment provides that the applied adhesive film does not exist in a form dissolved in an organic solvent.

[0080] The adhesive coating preferably consists of an adhesive having a significantly higher viscosity under equivalent firing conditions, particularly a significantly higher complex viscosity immediately before the start of chemical cross-linking, compared to commercially available fired resin systems known to those skilled in the art, as illustrated by the test results provided below. As a result, at the temperature reached during the process of the method according to the invention or its developments, the adhesive does not liquefy, but at most plasticizes or softens, with the advantage that the adhesive remains completely within the stack of molded parts.

[0081] In particular, it is preferred to use an adhesive that is not a hot melt adhesive, i.e., an adhesive that does not become liquid at the aforementioned activation temperature up to 180°C.

[0082] Particularly preferably, an adhesive having a complex viscosity of 8 Pa·s or more, preferably 10 Pa·s or more, is used in the "complex viscosity (temperature)" curve immediately before the start of chemical crosslinking, that is, at the position of the local minimum closest to the temperature range of chemical crosslinking, for example. In the method according to the present invention or its development, an adhesive that does not fall below the above-mentioned complex viscosity at least at a temperature lower than the temperature at which chemical crosslinking starts means that the adhesive does not liquefy to cover a large area, and the adhesive becomes at most paste-like at the use temperature (especially the activation temperature used). This means that a laminate stack with excellent properties, particularly high accuracy in geometric dimensions, can be obtained. Such a laminate stack is also particularly suitable for implementing a method having a post-compression step, which further promotes high accuracy in geometric dimensions.

[0083] The adhesive preferably contains 60 parts by weight of an epoxy resin in the form of a solid resin, 0.5 to 15 parts by weight of a latent curing agent, and 1 to 15 parts by weight of a latent accelerator.

[0084] The adhesive preferably has 1 to 10 parts by weight of a latent curing agent, and particularly preferably 2 to 5 parts by weight of a latent curing agent.

[0085] The term "latent curing agent" refers to a substance that is used to cure an epoxy resin but must be activated, particularly by supplying chemical energy and / or thermal energy, for curing. The latent curing agent is added to the adhesive, for example, as a powdery solid.

[0086] The term "latent accelerator" means a substance that promotes the curing of an epoxy resin by a latent curing agent. The attribute of "latency" related to the accelerator is related to the fact that the accelerator also needs to be pre-activated by chemical energy and / or thermal energy in order to perform its function. The latent accelerator is added to the adhesive, for example, as a solid in powder form.

[0087] The above composition relates to a mixture of components present as specific parts by weight of solids for forming an adhesive mixture, which can be made into an adhesive capable of forming an adhesive film by dispersion and / or dissolution with a suitable liquid. In a usable state, i.e., in a form suitable for application, the adhesive having specific components preferably exists as a dispersion of the above composition in a dispersion medium, particularly an aqueous dispersion.

[0088] The metal sheet is provided with an adhesive film consisting of a heat-activated adhesive, so the metal sheet coated with the adhesive is used as a preliminary product in a manufacturing process having flexible adaptability for electromagnetic components (particularly stator packages or rotor packages). Since the adhesive must be heat-activated first, the adhesive function can be carried out at a desired time or in a desired method procedure, for example, after the lamella is separated from the metal sheet by punching. The lamella must be brought together (optionally, preferably, under surface pressure partially or entirely in a press and / or subsequent compression process) during the chemical curing reaction within a short time after activation so as to adhere. This is the only way to create a perfect, non-peeling, geometrically accurate, and mechanically stable stack.

[0089] In combination with the described adhesive composition, the metal sheet has a surface with a short potential activation time, for example, from 0.05 to 1 second, preferably from 0.3 to 1 second. These properties enable both relatively high temperature resistance and relatively high insulation ability and aging resistance.

[0090] The epoxy resin present in the adhesive used according to the present invention contains one or more epoxy resin components having one or more epoxy groups, and preferably at least one epoxy resin has a softening point higher than 50°C.

[0091] The epoxy resin can be an aliphatic epoxy resin, an alicyclic epoxy resin, or an aromatic epoxy resin. The aliphatic epoxy resin contains a component having both an aliphatic group and at least two epoxy resin groups.

[0092] Examples of aliphatic epoxy resins can include butanediol diglycidyl ether, hexanediol diglycidyl ether, dimethylpentanedioxide, butadiene dioxide, diethylene glycol diglycidyl ether, and the like.

[0093] Examples of alicyclic epoxy resins include, for example, 3 - cyclohexenylmethyl - 3 - cyclohexylcarboxylate diepoxide, 3,4 - epoxycyclohexylalkyl - 3’,4’ - epoxycyclohexanecarboxylate, 3,4 - epoxy - 6 - methylcyclohexylmethyl - 3’,4’ - epoxy - o - methylcyclohexanecarboxylate, vinylcyclohexane dioxide, bis(3,4 - epoxycyclohexylmethyl) adipate, dicyclopentadiene dioxide, and 1,2 - epoxy - 6 - (2,3 - epoxypropoxy) hexahydro - 4,7 - methanoindane.

[0094] Examples of aromatic epoxy resins include, for example, bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, biphenyl epoxy resin, bisphenol epoxy resin, 4,4’ - biphenoline epoxy resin, divinylbenzene dioxide, 2 - glycidylphenyl glycidyl ether, and tetraglycidyl methylene dianiline.

[0095] In a preferred embodiment of the present invention, the epoxy resin is bisphenol A epoxy resin.

[0096] The latent curing agent used is preferably a substance or mixture that causes a curing reaction with the epoxy resin of the adhesive at a temperature in the range of 80°C to 200°C.

[0097] The hardener can include dicyandiamide, aziridine derivatives, triazine derivatives, imidazolines, imidazoles, o-tolylbiguanide, cyclic amidine, organic hexafluoroantimonate or hexafluorophosphate compounds, or BF3 amine complexes. These compounds can be used alone or in combination.

[0098] For example, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2’-methylimidazolyl-(1’)]-ethyl-s-triazine, 2,4-diamino-6-[2’-undecylimidazolyl-(1’)]-ethyl-s-triazine, 2,4-diamino-6-[2’-ethyl-4’-methylimidazolyl-(1’)]-ethyl-s-2,4-diamino-6-[2”-methylimidazolyl-(1’)]-ethyl-s-triazine, 2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, (1-dodecyl-2-methyl-3-benzyl)imidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, 2,4-diamino-6-vinyl-1,3,5-triazine, isocyanate adduct of 2,4-diamino-6-vinyl-1,3,5-triazine, 2,4-diamino-6-methacryloyloxyethyl-1,3,5-triazine, isocyanate adduct of 2,4-diamino-6-methacryloyloxyethyl-1,3,5-triazine, 1,3,5-triazine, 2,4-diamino-6-methyl-1,3,5-triazine, 2,4-diamino-6-nonyl-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-dimethoxy-6-methyl-1,3,5-triazine, 2,4-dimethoxy-6-phenyl-1,3,5-triazine, 2-amino-4,6-dimethyl-1,3,5-triazine, 2-amino-4-dimethylamino-6-methyl-1,3,It includes 5 - triazine, 2 - amino - 4 - ethoxy - 6 - methyl - 1,3,5 - triazine, 2 - amino - 4 - ethyl - 6 - methoxy - 1,3,5 - triazine, 2 - amino - 4 - methoxy - 6 - methyl - 1,3,5 - triazine, 2 - amino - 4 - methyl - 6 - phenyl - 1,3,5 - triazine, 2 - chloro - 4,6 - dimethoxy - 1,3,5 - triazine, 2 - ethylamino - 4 - methoxy - 6 - methyl - 1,3,5 - triazine, and 1 - o - tolylbiguanide.,

[0099] In a preferred embodiment of the present invention, the accelerator includes a urea derivative and / or an imidazole.

[0100] Also, the adhesive composition according to the present invention can include additional components.

[0101] Preferably, the curing agent includes dicyandiamide, imidazole, a BF3 amine complex, or a combination thereof.

[0102] In one embodiment, the adhesive can include 1 to 10 parts by weight of a latent accelerator, preferably 1 to 5 parts by weight of a latent accelerator, and particularly preferably 1 to 4 parts by weight of a latent accelerator. In another preferred embodiment, the adhesive further has 0.2 to 8 parts by weight of a dye, preferably 0.2 to 5 parts by weight of a dye. As a result, the visual appearance of the surface can be made more preferable. The dye can be selected from the group consisting of lamp black, iron oxide black pigment, or a water - soluble dye, or a mixture of a plurality of the above.

[0103] Preferably, the adhesive includes one or more of the insulating additives known to those skilled in the art. The term "insulating additive" refers to an additive provided specifically to increase the electrical resistance of the adhesive. The insulating additive can be contained in the adhesive in an amount of 1 to 10 parts by weight, preferably 1 to 5 parts by weight.

[0104] The adhesive preferably contains one or more rust inhibitors known to those skilled in the art. The rust inhibitor can be contained in the adhesive in an amount of 1 to 10 parts by weight, preferably 1 to 5 parts by weight.

[0105] In a modification of this method, the latent accelerator includes a urea derivative.

[0106] The latent accelerator contained in the adhesive preferably consists of 50% by weight or more, more preferably 90% by weight or more, and even more preferably entirely of urea derivatives.

[0107] Particularly preferably, the urea derivative is N,N-dimethylurea or N,N'-dimethylurea, or preferably a bifunctional urea derivative having two urea groups as functional groups, and very particularly preferably 4,4'-methylenebis-(phenyldimethylurea), or a mixture of multiple types thereof.

[0108] The latent accelerator contained in the adhesive preferably consists of at least 50% by weight, more preferably at least 90% by weight, even more preferably at least 98% by weight, and particularly preferably entirely of 4,4'-methylene-bis-(phenyldimethylurea).

[0109] In an alternative to this method, asymmetrically substituted ureas are also used in the same way or exclusively as the urea derivative.

[0110] In an alternative development, at least one, preferably two, particularly preferably three hydrogen atoms are each independently replaced by an alkyl group and / or a phenyl group, and a urea derivative is used according to the present invention. The alkyl group and the phenyl group may be further substituted. The alkyl group is preferably methyl, ethyl, propyl or butyl, preferably a methyl group; the phenyl group is phenyl, or preferably a deep substituent found also as Cool 1 of the aforementioned alkyl group at the 4-position. In a further alternative, in the context of the present invention, a bifunctional urea derivative is represented as the aforementioned derivative having two functional groups. A functional group is an atomic group that significantly determines the material properties, particularly the reaction behavior of the compound, and in particular, the functional group is involved in the reaction. Furthermore, the urea derivative to be used is halogen-free. Alternatively, the urea derivative to be used has two urea derivatives as functional groups. As a result, advantageously, the epoxy resin can be cured without the presence of dicyandiamide as a crosslinking agent.

[0111] A substance that can also be provided as a urea derivative is a compound represented by the following formula.

[0112] [Chemical formula]

[0113] (In the formula, R is hydrogen or the following formula,

[0114] [Chemical formula]

[0115] n = 0 or 1, preferably 1, X = O or S, preferably O, R1, R2 and R3 are each hydrogen, halogen, nitro group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted aryl group, or substituted or unsubstituted aryloxyl group, R4 is an alkyl group, alkenyl group, cycloalkyl group, cycloalkenyl group, aralkyl group which may optionally be substituted with halogen, hydroxyl or cyano, preferably methyl, ethyl, propyl, butyl, particularly preferably methyl, R5 is the same as R4 or is an alkoxyl group, Optionally, R5 may form a heterocyclic ring with R4.)

[0116] Alternatively, substances that can also be provided as urea derivatives are N,N-dimethyl-N'-(3,4-dichlorophenyl)urea, N,N-dimethyl-N'-(3-chloro-4-methylphenyl)urea, N,N-dimethyl-N'-(3-chloro-4-methoxyphenyl)urea, N,N-dimethyl-N'-(3-chloro-4-ethylphenyl)urea, N,N-dimethyl-N'-(4-methyl-3-nitrophenyl)urea, N-(N'-3,4-dichlorophenylcarbamoyl)morpholine, or N,N-dimethyl-N'-(3-chloro-4-methylphenyl)thiourea.

[0117] The urea derivative is preferably 4,4'-methylene-bis-(phenyldimethylurea), or a mixture of two, three or more of the foregoing. Preferably, such a mixture contains at least 10%, 25%, preferably 50%, 60%, 70%, 80% or 90% of 4,4'-methylene-bis-(phenyldimethylurea).

[0118] The advantages of the urea derivatives of the type mentioned can be found in British Patent Application Publication No. 1293142. The inventors have found that such derivatives can be excellently used in the manufacture of electromagnetic components.

[0119] The average particle size (arithmetic mean) of the urea derivative is preferably between 1 μm and 30 μm.

[0120] The adhesive coating can be applied to one or both sides of the metal sheet. When applying the adhesive coating to both sides, the thickness of the coating may be the same, but it is also possible to provide different thicknesses.

[0121] The preferred thickness of the adhesive film, that is, the thickness of the film on one side in the case of single-sided adhesion and the total thickness of the adhesive films on both sides in the case of double-sided adhesion, is between 1 μm and 20 μm, preferably between 2 μm and 10 μm. In particular, it is preferable that the total thickness is between 4 μm and 8 μm.

[0122] Applying the adhesive to one side is related to easier production on the surface of the device, while applying the adhesive to both sides is related to the advantage that when the individual lamellas made from the metal sheet are arranged one above the other, the adhesive surfaces are arranged in contact with each other, and as shown by tests, the adhesiveness is improved, thus achieving high mechanical stability of the electromagnetic component.

[0123] Particularly preferably, the first partial film on the surface of the first metal sheet and the second partial film having the second thickness on the surface of the second metal sheet are adapted to each other such that the first thickness is at least 1.5 times, preferably 2 times, the second thickness. In such a configuration, since the first thickness provides excellent insulation, the risk of an adhesive gap can be almost ignored. At the same time, the thinner of the two, that is, the second partial film applied with the second thickness, substantially helps to produce excellent adhesiveness.

[0124] A double-sided coating with a total thickness of the two coatings between 4 μm and 6 μm is highly particularly preferred. As shown by the examples produced, such a thin coating thickness is possible with the adhesives used in accordance with the invention or developments of the invention due to their high reactivity. Known stoving paint adhesives usually require a coating thickness of more than 6 μm (for example, a stoving coating on both sides, 5 μm on each side). This results in the advantage that parts (especially stators or rotors) can be produced from a metal sheet in accordance with the invention or its developments, having a significantly higher iron filling rate than parts produced by the stoving painting method. This advantage is a certain high efficiency of the electrical machine having such parts. However, it is possible to provide an adhesive coating with a total between 1 μm and 20 μm, preferably between 2 μm and 8 μm.

[0125] In a further alternative, a pretreatment agent, an adhesion promoter, a phosphating agent, and / or an insulator (for example in the form of an insulating resin coating) is arranged between the metal sheet and the adhesive layer and / or only an insulating resin coating is arranged on the metal sheet on the side opposite to the adhesive layer, or the surface is non-coated.

[0126] The metal sheet is particularly preferably designed as or separated from what is also called non-oriented electrical steel, so-called NO electrical steel. The non-oriented electrical steel strip contains, in addition to Fe and inevitable impurities, the following elements: 0.1 to 3.50 Si, 0.01 to 1.60 Al, 0.07 to 0.65 Mn, optionally up to 0.25 P (the numbers are all in weight %). Of course, it goes without saying that the sum of all alloy components and impurities is 100 weight %.

[0127] Particularly the following conditions are preferred: 2.3 to 3.40 Si, 0.3 to 1.1 Al, 0.07 to 0.250 Mn, optionally up to 0.030 P, and the remainder is Fe and inevitable impurities (the units are all in weight %). Of course, it goes without saying that the sum of all alloy components and impurities is 100 weight %.

[0128] The non-oriented electromagnetic steel strip or non-oriented metal sheet preferably has a longitudinal yield strength of 190 MPa to 610 MPa, a maximum tensile strength of 310 MPa to 740 MPa, a minimum elongation at break A80 of 6% to 48%, and a Hv5 hardness of 100 to 250, measured in accordance with DIN EN ISO 6892-1 under standard normal conditions.

[0129] In a particularly preferred embodiment, the material has a longitudinal yield strength at room temperature of 310 MPa to 600 MPa, a maximum tensile strength of 400 MPa to 640 MPa, and a minimum elongation at break A80 of 7% to 32%, and a Hv5 hardness of 130 to 250, measured in accordance with DIN EN ISO 6892-1. This material preferably exhibits an anisotropy in the range of 5% to 17% at P1.0; 400 Hz.

[0130] Sheet metal (especially electromagnetic steel strip) having a thickness between 0.05 mm and 2.5 mm is suitably and preferably used, with a thickness between 0.1 mm and 1.0 mm being preferred. In particular, a thickness of 0.15 to 0.4 mm is preferred.

[0131] Alternatively, the metal sheet may be a multilayer composite structure (sandwich) consisting of, for example, a metal sheet layer made from one of the aforementioned electromagnetic steel strips and one or more additional layers (for example, having an acoustic attenuation functional layer (for example, Bondal E)). Furthermore, the metal sheet can also have an acoustic attenuation functional layer (for example, Semi-Bondal E) applied to one or both sides, whereby the described adhesive system can be directly connected to the acoustic attenuation functional layer (for example, based on acrylate chemistry). It is known in the art that epoxy resin systems have good compatibility.

[0132] Alternatively, the metal sheet can have an acoustic attenuation functional layer on one side and an adhesive layer used in accordance with the present invention on the opposite side of the metal sheet.

[0133] In an advantageous development, steps C) to F) of the method according to the invention are carried out with a rise rate of at least 80 / min, preferably between 120 / min and 300 / min. If the requirements for bonded connections or smaller electrical components are lower, it is also possible to achieve a rise rate well above 300 / min.

[0134] One idea of the invention relates to a laminated stack for an electromechanical device or a stack section of a laminated stack, the stack being manufactured using a method of the kind described in one of the introductions or its developments. In particular, the laminated stack or stack section is designed as a stator or as a rotor.

[0135] The invention also includes an electromechanical device, in particular an electric motor, which has a stator and / or a rotor manufactured using a method according to the invention or one of its developments.

[0136] In one development, the electromechanical device has a stator and a rotor, the stator being a laminated stack manufactured, at least in part, using a method according to the invention or one of its developments, and the rotor being a component manufactured, at least in part, by a punching stack method known to those skilled in the art. The stator, which is particularly demanding in terms of electromagnetic efficiency, thereby provides excellent electromagnetic properties, while the rotor, which has lower requirements regarding its electromagnetic properties in many applications, is manufactured using a very cost-effective conventional punching stack method. As a result, an electromechanical device is provided that offers a good trade-off between good electromagnetic properties and cost-effective manufacturing.

[0137] Further details, features and advantages of the subject matter of the invention can be obtained from the following description in connection with the drawings which exemplify embodiments of the invention.

[0138] It goes without saying that the features described above and below can be used not only in the combinations shown, but also in other combinations or alone.

Examples

[0139] An example of a first embodiment of a method for manufacturing a laminate for an electric motor according to the present invention is shown in FIG. 1. A metal sheet already coated with an adhesive, that is, an non-oriented electromagnetic steel strip 1 coated with an adhesive of the type provided according to the present invention, is provided. This strip is conveyed into a series-type system. In the first station, a number of punching machines 4 cut out shaped parts 2 designed as rotor laminas or stator laminas. In subsequent stations, the shaped parts are irradiated using means 5 designed as an NIR radiation source for outputting infrared rays, and the adhesive coating on the shaped parts is activated by the resulting heating. The activation means 5 has a first infrared irradiator 5a and a second infrared irradiator 5b. The irradiator 5a irradiates radiation with wavelengths of 780 nm and 1200 nm, and the second irradiator irradiates radiation with wavelengths of 1200 nm and 3000 nm. By irradiating different wavelengths, a more uniform activation of the adhesive coating is achieved in the direction perpendicular to the sheet surface, and the time required for the activation of the adhesive coating is shortened, so that higher efficiency enables a higher acceleration rate.

[0140] Certain laminas are coated using a processing device 9 designed as an application roller in order to function as a target breaking point between individual stack stacks in a subsequent stack of shaped parts. Whenever the specified number of shaped parts is reached, in the representation shown in the plane of the paper, the application roller 9 moves towards the metal sheet and coats the next shaped part after the specified number reached in order to reduce or completely remove the effect of the adhesive coating. The coated shaped parts then have a target breaking point that can separate the stack of shaped parts into stack sections, and preferably in a continuous operation process, each of the stack sections represents a finished laminated stack. In the manufacture of the stack of shaped parts, the lamina 8 was the lamina corresponding to the planned number of shaped parts achieved. For this reason, punching oil was applied using an application roller 9 adapted as a processing device, thereby reducing the adhesive strength.

[0141] Next, the formed parts are extruded using the separating means 6 designed as a cutting die, collected in the positioning area and preliminarily fixed, and the stack 3 is formed in a positioned and / or angularly aligned state. That is, the lamellas with the activated adhesive coating simply adhere to each other by their own weight.

[0142] In the state of removal, the laminated stack is the stack section in the formed part stack where the adhesive application effect on the lamina 8 is reduced and is removed at the target breaking point 8. The stack section can be removed by its own weight or separated from the formed part stack with the assistance of a device or manually. In this embodiment, as the stack section 3' in the compression station 7, there are two separate stack sections that are post-compressed in subsequent processes.

[0143] Finally, in the compression station, compression is performed by the compression ram 7 until the adhesive is cured and the completed laminated stack can be removed.

[0144] Examples of the metal sheet according to the present invention and its advantageous behavior for the method according to the present invention are given in the tests carried out.

[0145] The following samples were produced. A sheet with a thickness of 0.5 mm and a length × width of 200 × 150 mm was produced from an electromagnetic steel strip M800 - 50A (according to EN10027 - 1) with a material code 1.0816 (according to EN10027 - 2).

[0146] Samples 0, 1, 2, and 3 were prepared. Samples 0, 1, and 2 are comparative samples and are coated with adhesives not according to the present invention. Sample 3 is the advantageous sample.

[0147] The prepared samples are sheets of the above type on which the adhesive was applied using a coating roller according to the following parameters.

[0148]

Table 1

[0149] Layer thickness Sample 0: 6 μm on the first side, 0 μm on the second side. Sample 1: 6 μm on the first side, 0 μm on the second side. Sample 2: 4 μm on the first side, 2 μm on the second side. Sample 3: 4 μm on the first side, 2 μm on the second side.

[0150] For each sample type, multiple samples were prepared. To test the long-term stability, two of the same samples were used to create 18 sandwich structures respectively.

[0151] Using a plate press with a plate area of 200 mm × 200 mm, with a surface pressure of 3 N / mm 2 Two samples of the same type were adhered with a surface pressure of, heated to 120 °C in an oven and held at 120 °C for 30 minutes to activate the adhesive. Then, eight samples were placed in the oven and stored at 40 °C. Samples were taken every week and shear value tests (based on DIN EN 1465) were carried out. Furthermore, shear value tests were also carried out on the samples stored at room temperature every week. The test results are shown in Figures 2a and 2b.

[0152] From these results, it can be seen that at room temperature, the composition used according to the present invention has better shear values than reference sample 0, sample 1 and sample 2. The sample 0 tested after 6 weeks had a significantly decreased shear value; after 8 weeks, the shear value of sample 0 was 0.

[0153] For storage at 40 °C, the shear value of reference sample 0 became 0 at the latest after 1 week. That is, it can be seen that this sample does not have storage stability at 40 °C. Samples 1 and 2 after 2 weeks showed almost unchanged good shear values of 7.0 N / mm 2 or more, but began to deteriorate significantly after 3 weeks of storage.

[0154] In any case, the shear value of Sample 2 with both sides coated is higher than that of Sample 1 with only one side coated. This proves a particularly advantageous effect when the metal plate is coated on both sides.

[0155] In particular, it can be seen that Sample 3 has the best storage stability as its shear value hardly changes even after 4 weeks of storage at 40°C. The only sample obtained was a sandwich sheet whose shear value did not change even after 4 weeks of storage at 40°C. At the time of filing, this test is still ongoing.

[0156] Furthermore, the shear value test was also conducted after heating the completed sandwich product to the test temperature and holding it at that temperature for a short time.

[0157]

Table 2

[0158] As a result, it can be seen that both Sample 2 and Sample 3 can withstand high temperatures up to 200°C for a certain period without any loss of mechanical stability. In particular, it can be seen that the shear value of Sample 3 is significantly higher than that of Comparative Sample 2.

[0159] For reference, when Sample 0 was subjected to a temperature test, it was shown that a shear value of about 0.90 N / mm was obtained after heating to 150°C. Based on Sample 3, it was found that the metal sheet according to the present invention is more suitable for manufacturing laminated stacks with higher temperature stability compared to known metal sheets. 2 Based on Sample 3, it was found that the metal sheet according to the present invention is more suitable for manufacturing laminated stacks with higher temperature stability compared to known metal sheets.

[0160] In FIG. 3, it can be seen from the tests carried out that the advantageous adhesive having the same composition as that used in Sample 3 has a significantly higher complex viscosity than commercially available baking paints even at temperatures in the region of 100°C. In particular, the value of the complex viscosity of 10.74 Pa·s immediately before the crosslinking reaction is a significantly higher value than that obtained with conventional baking paints. This supports the fact that since the adhesive does not liquefy and at most undergoes a transition to a paste-like behavior, a metal sheet having such an adhesive film can be advantageously used in the method according to the invention providing post-compression, particularly in its deployment. As a result, no significant flow of the adhesive from the laminated stack is observed, and corresponding advantages are obtained, in particular good adhesion that can be verified, for example, in a top pull test.

[0161] In other tests (not shown) in the 70-day long-term test, Sample 3 was qualitatively equivalent to each of Samples 0 to 2 with respect to oil resistance, that is, it was confirmed that the adhesive force between the lamellae did not decrease even when stored in oil at 150°C for 70 days in the shear value test.

Claims

1. 1. A method of manufacturing a lamination stack for an electric machine, the lamination stack being either a stator core or a rotor package, the method comprising: A) providing a metal sheet having an at least partially curable polymer-based adhesive coating, or a plurality of metal sheets having at least partially curable polymer-based adhesive coatings; B) conveying the metal sheet into an in-line system, the in-line system including at least one cutting means, a separating means, and an activating means for activating the adhesive coating; C) cutting, by means of at least one cutting means, shaped parts designed as stator or rotor lamellae from the metal sheet provided in step A; D) activating the adhesive coating of the molded part formed in step C) using an activation means for activating the adhesive coating of the molded part; E) separating the shaped part from the metal sheet using a separating means; F) placing molded parts in a positioning area for forming a stack of molded parts; G) repeating steps C) to F) to successively fill the positioning area with molded parts, whereby after reaching a predetermined number of molded parts, and before carrying out step F) for a subsequent molded part, using the treatment device to at least partially supply treatment liquid to said subsequent molded part, in order to reduce the effect of the adhesive coating of this subsequent molded part, and as a result of the reduced effect of the adhesive coating, to result in an improved separation in the positioning area between the stack section below the reduced effect adhesive coating and the stack section above the reduced effect adhesive coating. Including, After separation of the stack sections, the stack sections are post-compressed in a press with a pressure on the end faces that is constant on the end faces, i.e., perpendicular to the lamella surface, the pressure being 10,000 N / (14,000 mm 2 ) and 200,000N / (10,000mm 2 ) and The adhesive coating comprises 60 parts by weight of an epoxide resin in the form of a solid resin, 0.5 to 15 parts by weight of a latent hardener, and 1 to 15 parts by weight of a latent accelerator. A method comprising:

2. 2. The method of claim 1, wherein the activating means includes a first infrared irradiator for irradiating the adhesive coating with infrared light, thereby activating the adhesive coating, or the activating means includes an induction heater.

3. 3. The method of claim 1 or 2, wherein the treatment liquid is a separating fluid and the treatment device is an applicator device that applies the separating fluid to the adhesive coating as a treatment of the adhesive coating.

4. 3. The method according to claim 1 or 2, characterized in that the treatment liquid is a cooling fluid and the treatment device is a wetting unit which applies the cooling fluid to the adhesive coating as a treatment of the adhesive coating.

5. 3. The method according to claim 1, wherein the treatment liquid is a separation liquid in the form of a punching oil.

6. 6. The method according to claim 1, characterized in that after separating the stack sections, the stack sections are post-compressed at a temperature between 30°C and 180°C.

7. 7. The method of claim 6, characterized in that the stack sections are post-compressed at a temperature between 40°C and 120°C.

8. 8. The method of claim 7, characterized in that the stack sections are post-compressed at a temperature between 50°C and 100°C.

9. After the stack sections were separated, the stack sections were post-compressed with a pressure on the end faces that was constant on the end faces, and the pressure was 50,000 N / (14,000 mm 2 ) and 150,000N / (10,000mm 2 9. The method according to claim 1, wherein the ratio of the first to the second is between 0 and 1.

10. 10. The method according to claim 1, wherein the adhesive coating is applied to the metal sheet as an aqueous dispersion and / or the adhesive coating has a complex viscosity of 8 Pa×s or more immediately prior to the onset of chemical crosslinking.

11. 11. The method according to any one of claims 1 to 10, characterized in that the adhesive coating comprises 60 parts by weight of an epoxide resin in the form of a solid resin, 1 to 10 parts by weight of a latent hardener and 1 to 15 parts by weight of a latent accelerator.

12. 12. The method according to any of the preceding claims, characterized in that the metal sheet provided in step A) is provided with an adhesive coating on both sides.

13. 13. The method of claim 1, wherein the latent accelerator comprises a urea derivative.

14. 14. The method of claim 13, wherein the urea derivative comprises or consists of an asymmetrically substituted urea.

15. The method according to claim 13 or 14, characterized in that the urea derivative is N,N-dimethylurea, N,N'-dimethylurea, or a bifunctional urea derivative.

16. The method according to any one of claims 13 to 15, wherein the urea derivative is a bifunctional urea derivative having two urea groups as functional groups.

17. The method according to any one of claims 13 to 16, characterized in that the urea derivative is 4,4'-methylene-bis-(phenyldimethylurea).

18. 18. The method according to any one of claims 1 to 17, characterized in that the latent accelerator contained in the adhesive consists of at least 50% by weight of 4,4'-methylene-bis-(phenyldimethylurea).

19. 19. The method according to any one of claims 1 to 18, characterized in that the latent accelerator contained in the adhesive consists of at least 90% by weight of 4,4'-methylene-bis-(phenyldimethylurea).

20. 20. The method according to any one of claims 1 to 19, characterized in that the latent accelerator contained in the adhesive consists of at least 98% by weight of 4,4'-methylene-bis-(phenyldimethylurea).

21. The urea derivative is a compound of the formula 【Chemistry 1】 wherein R is hydrogen or the following formula: 【Chemistry 2】 n=0 or 1; X=O or S; R 1 , R 2 and R 3 each represents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aryloxyl group; R 4 is an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aralkyl group, a halogen-substituted aralkyl group, a hydroxyl group, or a cyano group; R 5 is R 4 or an alkoxy group, R 5 and R 4 may form a heterocycle; or or the urea derivative is N,N-dimethyl-N'-(3,4-dichlorophenyl)urea, N,N-dimethyl-N'-(3-chloro-4-methylphenyl)urea, N,N-dimethyl-N'-(3-chloro-4-methoxyphenyl)urea, N,N-dimethyl-N'-(3-chloro-4-ethylphenyl)urea, N,N-dimethyl-N'-(4-methyl-3-nitrophenyl)urea, N-(N'-3,4-dichlorophenylcarbamoyl)morpholine, or N,N-dimethyl-N'-(3-chloro-4-methylphenyl)thiourea; The urea derivative is a mixture of two, three or more of the above-mentioned compounds, containing at least 10% of 4,4'-methylene-bis-(phenyldimethylurea).

14. The method according to claim 13.

22. 22. The method of any one of claims 1 to 21, wherein the epoxide resin comprises one or more epoxide resins having two or more epoxy groups.

23. The epoxide resin is an aliphatic epoxide resin, a cycloaliphatic epoxide resin, or an aromatic epoxide resin, or The epoxide resin is an aliphatic epoxide resin that includes a component having an aliphatic group and at least two epoxy groups, or the epoxide resin is an aliphatic epoxide resin selected from butanediol diglycidyl ether, hexanediol diglycidyl ether, dimethylpentane dioxide, butadiene dioxide, and diethylene glycol diglycidyl ether; or the epoxide resin is a cycloaliphatic epoxide resin selected from 3-cyclohexenylmethyl-3-cyclohexylcarboxylate diepoxide, 3,4-epoxycyclohexylalkyl-3',4'-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-o-methylcyclohexanecarboxylate, vinylcyclohexanedioxide, bis(3,4-epoxycyclohexylmethyl)adipate, dicyclopentadienedioxide, and 1,2-epoxy-6-(2,3-epoxypropoxy)hexahydro-4,7-methanoindane, or The epoxide resin is an aromatic epoxide resin selected from bisphenol A epoxide resin, bisphenol F epoxide resin, phenol novolac epoxide resin, cresol novolac epoxide resin, biphenyl epoxide resin, biphenol epoxide resin, 4,4'-biphenolline epoxide resin, divinylbenzene dioxide, 2-glycidylphenyl glycidyl ether, and tetraglycidylmethylene dianiline.

23. The method according to any one of claims 1 to 22.

24. 24. The method according to any one of claims 1 to 23, wherein the epoxide resin is a bisphenol A epoxide resin.

25. 25. The method of any one of claims 1 to 24, wherein the curing agent comprises dicyandiimide, imidazole, BF3 amine complex, or a combination thereof.

26. 26. The method according to claim 1, wherein steps C) to F) are carried out at an increasing rate of at least 80 min-1.

27. 27. The method according to claim 1, characterized in that from a stack of molded parts formed by filling the positioning area with molded parts, stack sections separated from one another by a reduced-effective adhesive film or stack sections provided with a targeted breaking point are removed separately.

28. 28. A lamination stack for an electric machine, characterized in that it is manufactured as a stack section using the method according to claim 27 and is designed as a stator or rotor.

29. 29. An electric machine, in particular an electric motor, comprising a stator and / or a rotor according to claim 28.

30. 30. An electric machine according to claim 29, comprising a stator and a rotor, the stator being partly or completely a laminate stack according to claim 28, and the rotor being partly or completely a component manufactured by means of stamping and stacking.

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