Method and apparatus for applying particle size controlled liquid coatings onto variable geometry sheet stacks - Patents.com

Abstract

The present invention comprises a method and apparatus for applying particle size controlled liquid coatings onto stacked and compressed sheets of various geometric shapes. Such coatings can be adhesives, accelerators, insulators or thermal barriers. The method and apparatus allows for the measurement of the particle size of the suspended particles of the coating after each application in order to control the amount used.

Description

[Technical Field]

[0001] The present invention relates to the field of manufacturing laminated cores for electric motors, and in particular to a method and apparatus for applying particle size controlled liquid coatings such as adhesives, accelerators, insulators, or thermal barriers onto stacked and compressed laminate sheets of various geometric shapes. [Background technology]

[0002] The method and apparatus of the present invention relate to the manufacture of laminated cores for electric motors, which are formed from laminated magnetic sheets and stacked in a cylindrical or ring shape to form rotors and stators. The laminated sheets must be bonded together, for example, using an adhesive coating, so that the magnetic properties of the material are maintained while improving insulation between the sheets and the strength of the core.

[0003] The adhesive coating is applied to one or both sides of the laminated sheets and occupies the space within the stack of laminated sheets.

[0004] It is known in the prior art that the space factor is the ratio of the effective cross-sectional area of ​​the rotor or stator core to the total physical cross-sectional area of ​​the core, taking into account that the adhesive covers a finite space, and as a result the effective area occupied by the magnetic flux is smaller than the total physical area of ​​the core.

[0005] The space factor indicates the ability of a laminated motor core to pass electrical flux. It is highly dependent on the core's manufacturing process, including the pressure applied to the laminations, the thickness of the laminations, and the methods used to join the laminations and prevent them from contacting each other. Space factor can be calculated from the weight, volume, and density of the laminated stack materials.

[0006] Laminated cores always have a space factor of less than 1, since a space factor of 1 means there are no laminations at all. Stator cores typically have a space factor close to 0.95, while cores made of amorphous metals have a space factor of about 0.8, and silicon steel typically has a space factor of 0.96, although this depends on the other core components. It is possible to reduce the space occupied by the adhesive coating that bonds the laminations in an electric core, but this can weaken the bond strength between the laminations if the amount of adhesive coating used is reduced too much.

[0007] Similarly, determining the amount of coating used in these processes is based on knowledge of the material being used and the number of parts being processed. The amount of material used is typically divided by the number of parts being coated to obtain the amount used per part. However, this method is inaccurate. The method and apparatus of the present invention solves these problems.

[0008] Adhesives for forming laminated core packs are often applied during the die-cutting process, as is the case in Japanese Patent No. 3822020, Chinese Patent No. 101673986(B), and Japanese Patent No. 4648765, among others.

[0009] Mexican Patent No. 375091(B) (also published as U.S. Pat. No. 9,531,223(B2)) describes a method for producing stacks of laminates with controlled heights by applying adhesive and primer in the form of small dots, droplets, or sprays to one or both sides of the laminate sheets, with the adhesive and primer being applied directly onto the laminate using an application head, die, roller, cylinder, or pad over a partial or full surface area by a driver based on the punch stroke. The method takes into account the total height of the laminate package based on the number of sheets being compressed, but does not affect the space factor or provide any means for controlling the amount of adhesive used per application.

[0010] The same applies to U.S. Patent No. 10,230,291 (B2), U.S. Patent No. 10,720,802 (B2), U.S. Patent Application Publication No. 2019322093 (A1), U.S. Patent No. 8,474,129 (B2), European Patent No. 3,535,836 (B1), French Patent No. 3,042,923 (B1), and U.S. Patent No. 6,301,773 (B1).

[0011] Meanwhile, U.S. Patent Application Publication No. 20160067728(A1) describes a method for forming a layer of adhesive coating on a workpiece, which measures the weight of the adhesive on the workpiece to obtain data on the amount of adhesive used and enable real-time adjustment of the amount of adhesive sprayed. The measurement also allows for estimation of the thickness of the adhesive layer. The method directly measures the sprayed adhesive once it adheres to the applied part.

[0012] US Patent Application Publication No. 20050001869(A1) uses a calibration surface to meter the adhesive dots before applying them to a substrate at a given speed.

[0013] U.S. Patent No. 4,361,110(A) describes an apparatus and system for applying adhesive to a work surface that measures light reflected from the work surface to determine the rate of coating deposited. The apparatus and system measures the light reflection on the coated surface and controls the amount of coating used.

[0014] DE 10048749 A1 describes a robotic device for applying adhesive to a workpiece surface, which acquires information by means of an image evaluation unit having multiple digital cameras configured as infrared cameras aimed at the surface to be coated. The unit generates information for comparing the results with theoretical values ​​in order to adjust the amount of adhesive sprayed directly onto the workpiece. The image of the sprayed surface is evaluated.

[0015] Another patent for measuring the amount of adhesive or viscous liquid sprayed onto a work surface is US Patent Application Publication No. 20020151042(A1). Summary of the Invention

[0016] Some adhesive coatings are used in combination with accelerators or diluents to modify their behavior or to combine two or more adhesives with different cure times and bond strengths. The present invention proposes a different method for measuring the adhesive used. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram of the process. [Figure 2] FIG. 1 is an isometric view of the device with the lid open. [Figure 3] FIG. [Figure 4] FIG. 1 illustrates the use of the device in combination with a punch press. [Figure 5] FIG. 1 illustrates the use of the device in a workstation. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention comprises a method and apparatus for applying particle-size-controlled liquid coatings, such as adhesives, accelerators, insulators, or barriers, to stacked and compressed laminated sheets of various geometries. The method and apparatus allow for measurement of the particle size of the suspended particles in the coating after each application to control application rate and measure efficiency. The method and apparatus can measure and control the amount of coating applied using fluids with viscosities ranging from 100 to 3500 centipoise.

[0019] A method for applying a particle size-controlled liquid coating onto a variable geometry laminate sheet comprises the steps of: using as a feed material (1.1) a continuous laminate strip and / or a single laminate sheet of variable geometry and / or a stacked laminate sheet pack of variable geometry (1); selecting and positioning at least one coating pattern-defining mask (2.1) according to the geometry of the resulting part or the geometry of the feed material (2); setting operating parameters associated with the selected coating pattern-defining mask (2.1); placing the feed material (1.1) in a predetermined position to receive the coating (4); and placing at least one particle generation chamber (6.1) at an application location. (5), pressurizing the particle generation chamber (6), generating a particle size of the floating liquid coating (7), measuring the particle size of the floating liquid coating (8), determining whether the particle size of the floating liquid coating is within a set range (9), and, if necessary, changing the set particle size generation parameters of the floating liquid coating (10), releasing the pressure in the particle generation chamber to deposit this volume of floating particles onto any surface of the feed material (11), positioning the particle generation chamber (6.1) to allow displacement of the feed material (12), and displacing the coated feed material (13).

[0020] The feed material (1.1) may be provided in the form of at least one continuous laminate strip and / or as a single laminate sheet of various geometric shapes and / or as a stack of stacked laminate sheets (1). This may be done manually or automatically. The coating pattern-defining mask (2.1) consists of a flat or volumetric area that defines the area where the suspended liquid coating is to be deposited on the surface of the feed material (1.1).

[0021] The coating pattern-defining mask (2.1) can be selected from several different shaped masks, each suited to one or more geometries of the resulting part or feed material (2).

[0022] The coating pattern defining mask (2.1) is placed at the end of the particle generation chamber (6.1) in contact with the surface of the feed material to be coated by the suspended particles.

[0023] The selection and positioning of the coating pattern definition mask (2.1) can be done manually or automatically, and is done whenever the geometry of the resulting part or the geometry of the feed material changes.

[0024] The predetermined operating parameters that may be set (3) are (a) the internal pressure of the particle generation chamber, (b) the pressure at which the liquid coating is inside the particle generation device (6.2), (c) the ambient temperature, (d) the open time of the particle generation device (6.2), and (e) the minimum and maximum particle size range in suspension, as appropriate.

[0025] The operating parameters suitable for each geometry of the feed material (1.1) and associated with at least one coating pattern-defining mask are known based on pre-production performance tests, and are set manually or automatically and stored in the control device (3.1).

[0026] The feed material (1.1), in the form of at least one continuous laminate strip, or as a single laminate sheet, or as a bundle of laminate sheets, can be placed in position to receive the coating (4) by any means, either manually or automatically.

[0027] The particle generation chamber (6.1) is an enclosed space of any geometric shape, pressurized to contain the coating particles, which remain suspended in air until they are applied.

[0028] To position the particle generation chamber at the application position (5), it is necessary that the coating pattern-defining mask (2.1) be in contact with the surface of the feed material to be coated. The positioning of the particle generation chamber (6.1) at the application position can be accomplished manually or automatically by any means, corresponding to any positioning that allows the mask to be in contact with the surface of the feed material (1.1) to be coated.

[0029] Pressurization of the particle generation chamber (6.1) is achieved by one or more pressure valves (6.3) that inject pressurized air into the particle generation chamber (6.1). The pressure reached in the particle generation chamber (6.1) is preferably between 3 and 12 bar, and serves to release the particles of the liquid coating suspended in the air inside the particle generation chamber (6.1) and to move and deposit them on any surface of the feed material (1.1). The pressure is released through at least one application damper (6.4).

[0030] Particle generation of the suspended liquid coating (7) is carried out inside at least one particle generation chamber (6.1) by at least one valve (6.2) using set operating parameters which can be automatically adjusted as needed based on particle size measurements (8) of the suspended particles of the generated liquid coating.

[0031] Measurement (8) of the airborne particle size of the produced liquid coating is carried out inside the particle generation chamber (6.1) by at least one measuring device (8.1) which estimates the equivalent mean particle size of the airborne particles by means of a laser light emitting lamp (8.2) directed towards a CCD sensor (8.3) which measures the scattering of laser light reflected by the particles of the airborne liquid coating.

[0032] The measurements are carried out periodically and transmitted to the control device (8.1).

[0033] The above measurements serve as the basis for determining (9) whether the particle size produced falls within a set range corresponding to the minimum and maximum suspended particle sizes indicated as acceptable.

[0034] If the measured particle size is within the set minimum and maximum range (9), the same operating parameters are maintained. If the measured particle size (8) is outside the set minimum and maximum range (9), the control device (3.1) adjusts the set operating parameters (3). The adjustment is performed automatically according to the predetermined operation and selection.

[0035] Once the airborne particles have been measured, the control device (3.1) opens the application flap (6.4).

[0036] The application (11) of the generated particles is carried out on a surface limited by the selected coating pattern definition mask (2.1) and corresponding to the desired surface of the feed material.

[0037] When pressure is released from the particle generation chamber (6.1) by opening at least one application hatch (6.4), the suspended liquid coating particles pass through the application hatch (6.4) and through the coating pattern defining mask (2.1) and are deposited on the exposed surface of the delivery material (1.1) so that the remaining portions of the surface of the delivery material (1.1) are not coated.

[0038] After application of a given amount of particles in a liquid coating in suspension (11), the particle generation chamber is placed in a position (12) that allows displacement of the delivered material (13).

[0039] The generation and application of the suspended particles is done indirectly and involves pressurizing a particle generation chamber (6), generating particles from the suspended liquid coating by releasing pressure from the particle generation chamber (11) (7), measuring the particle size of the suspended liquid coating (8), and transferring and depositing the suspended particles onto a feed material (1.1) by contact or other means.

[0040] The described methods may include one or more stages of particle generation and application using the same or different types of coatings, for example, by adding more particle generation chambers.

[0041] The apparatus for particle size controlled application of liquid coatings onto laminated sheets of variable geometry comprises at least one particle generation chamber (6.1), at least one coating pattern defining mask (2.1), at least one particle generation device (6.2), at least one particle size measuring device (8.1), at least one particle generation chamber pressure regulating valve (6.3), at least one application hatch (6.4), and at least one control device (3.1).

[0042] The particle generation chamber (6.1) comprises a closed space of any geometric shape, at a pressure higher than atmospheric pressure, preferably between 3 and 12 bar, in which the liquid coating particles are held suspended in air. The pressure is provided by at least one pressure regulating valve (6.3) in the particle generation chamber, which injects pressurized air prior to particle generation.

[0043] Inside the particle generation chamber (6.1) there are installed at least one particle generation device (6.2), a particle measurement device (8.1) and at least one coating hatch (6.4).

[0044] The particle generator (6.2) is operated by a control valve (8.1) that determines the opening time, which in turn regulates the pressure of the liquid coating inside the particle generator (6.2) by means of a pump.

[0045] The particle generator (6.2) can be pneumatic, ultrasonic, or any other type of configuration capable of handling fluids with viscosities anywhere in the range of 100-3500 centipoise.

[0046] The combination of the open time of the particle generator and the pressure of the liquid coating allows the generation of a specific particle size of the liquid coating inside the chamber (6.1) that remains suspended in air.

[0047] Inside the particle generation chamber (6.1) there is also at least one suspended particle size measuring device (8.1), which consists of a laser light emitting lamp (8.2) directed towards a CCD sensor (8.3) that measures the scattering of the laser light reflected at a specific angle depending on the particle size of the suspended liquid coating.

[0048] The particle size measuring device (8.1) generates a signal that is sent to the control device (3.1) for comparing the received measurements with set operating parameters, specifically the minimum and maximum particle size ranges in suspension that are indicated as suitable for application.

[0049] If the airborne particle size measurements are within the set range, the same operating parameters are maintained; if not, the necessary adjustments are automatically made.

[0050] Suspended particles larger than the specified particle size result in wasted liquid coating and take up more space in the stack of rolled sheets, while a lower amount of suspended particles reduces the bond strength of the adhesive coating.

[0051] Once the airborne particle size has been measured, at least one application flap (6.4) opens, releasing the pressure and allowing the airborne liquid coating particles to pass through and move towards the coating pattern definition mask (2.1). The application hatch (6.4) remains closed at all times and is only opened for particle application (11).

[0052] Measurement of the airborne particle size allows the application of airborne particles to be maintained within a set operating range and allows immediate adjustment of operating parameters by the control device (8.1).

[0053] The coating pattern-defining mask (2.1) exposes areas where coating particles are to be applied according to the specific geometry of the delivery material (1.1). The size and shape of the uncovered areas of the coating pattern-defining mask (2.1) influence the operating parameters.

[0054] The coating pattern-defining mask (2.1) must be in contact with the surface (1.1) of the feed material to be coated in order to deposit particles of the liquid coating in suspension in the chamber (6.1) onto the surface (1.1) of the feed material.

[0055] The generation and application of the liquid coating is therefore indirect: it begins inside a pressurized particle generator chamber (6.1) that momentarily keeps the particles suspended in air, passes through a coating hatch (6.4), and the coating pattern is defined by a coating pattern-defining mask (2.1) on the feed material (1.1).

[0056] Once the coating has been applied to any surface of the delivery material (1.1), the particle generation chamber (6.1) is placed in a position that allows movement of the delivery material. The placement of the particle generation chamber (6.1) in a position that allows movement of the delivery material (1.1) to a position other than the application position can be achieved manually or automatically by any means and corresponds to any placement that allows movement of the delivery material (1.1) to a position other than the application position. The best way forward

[0057] The method and apparatus of the present invention may be used in conjunction with a punch press (5.4), as shown in Figure 4. In this method, a continuous strip of laminated magnetic material is used as the feed material (1.1) and fed into the punch press.

[0058] The particle generation chamber (6.1) is housed inside the die, either on the punch side (5.2) if application is from top to bottom, or on the die side (5.3) if application is from bottom to top.

[0059] At least one coating pattern defining mask (2.1) is selected and positioned according to the geometry of the part to be stamped (2).

[0060] The coating pattern-defining mask (2.1) is positioned flush with the surface of the punch (5.2) or die (5.3) and contacts the feed material (1.1) simultaneously with the punch (5.2) or die (5.3).

[0061] The operating parameters associated with the selected coating pattern defining mask (2.1) are set (3).

[0062] In this embodiment, the operating parameters that are set (3) are: (a) the internal pressure of the particle generation chamber (preferably 3-12 bar), (b) the pressure at which the liquid coating is inside the particle generation device (6.2) (preferably 3-12 bar), (c) the ambient temperature, (d) the open time of the particle generation device (6.2), and (e) the minimum and maximum range of the suspended particle size. The latter two depend on the geometry of the part being punched. The control system compensates for extreme temperature variations.

[0063] The feed material (1.1) is automatically placed in position to receive the coating (4) by rollers (1.2) that align the laminated strip within the punch press and advance the laminated strip to different positions.

[0064] The press serves to shape the laminate and places (5) at least one particle generation chamber (6.1) in a position to apply and to allow displacement (12) of the feed material.

[0065] When the particle generation chamber (6.1) is placed in the matrix (5.3), the movements for positioning the particle generation chamber are small and are made within the matrix (5.3) itself, as shown in Figures 4A and 4B, in the space (5.5) below the particle generation chamber (6.1) when it is in the application position (5), and in the space (5.5) above the particle generation chamber (6.1) when it is in a position allowing the displacement (12) of the feed material (1.1).

[0066] When the particle generation chamber (6.1) is next to the punch (5.2), the movement to position the particle generation chamber (6.1) is performed by the press as part of the up and down movement of the punch (5.2), which is positioned so that when it descends it contacts the feed material (1.1) at the application position and when it ascends it allows the movement (12) of the feed material (1.1).

[0067] The speed of the press is related to the speed of particle generation and application, which includes the steps of pressurizing the particle generation chamber (6), generating a particle size of the suspended liquid coating (7), measuring the particle size of the suspended liquid coating (8), and transferring the suspended particle population onto the feed material (1.1) by releasing pressure from the particle generation chamber (11).

[0068] A typical press is expected to operate within the range of 120-200 strokes per minute. If the particle size measurement of the produced liquid coating is outside the set range (9), the control system (3.1) automatically corrects the set parameters (10).

[0069] The method and apparatus of the present invention may also be used to form a manual, semi-manual or automated workstation as shown in Figure 5. In this configuration, single laminated sheets of variable geometry and / or stacked laminated sheet packs of variable geometry are used as the feed material (1.1) (1).

[0070] The particle generation chamber (6.1) is positioned above the feed material (1.1) by a support (5.1) and a linear actuator that can raise or lower it.

[0071] At least one coating pattern definition mask (2.1) is selected and positioned (2) according to the geometry of the loosely stacked sheets and / or stacked stacked sheet packs (1.1). In this method, the coating pattern definition mask (2.1) is placed at the bottom of the particle generation chamber (6.1). Operating parameters associated with the selected coating pattern definition mask (2.1) are set (3).

[0072] In this method, the operating parameters to be set (3) are (a) the internal pressure of the particle generation chamber (preferably 3-12 bar), (b) the pressure at which the liquid coating is inside the particle generation device (6.2) (preferably 3-12 bar), (c) the ambient temperature, (d) the open time of the particle generation device (6.2), and (e) the minimum and maximum particle size range depending on the geometry of the part being punched. The control system compensates for extreme temperature variations.

[0073] The feed material (1.1) is manually or automatically positioned (4) on an alignment device (1.3) where single laminated sheets and / or stacks of laminated sheets are stacked. This alignment device (1.3) determines the position to receive the coating (4).

[0074] The particle generation chamber is lowered to a coating position (5) where a coating pattern-defining mask (2.1) contacts the surface of the feed material (1.1) on the opposite side of the particle generation chamber.

[0075] Particle generation and application includes pressurizing the particle generation chamber (6), generating a particle size of the suspended liquid coating (7), measuring the particle size of the suspended liquid coating (8), transferring the suspended particle cloud onto the feed material (1.1) by releasing pressure from the particle generation chamber (11), and opening the application hatch (6.4).

[0076] If the particle size measurement of the produced liquid coating is outside the set range (9), the control system (3.1) automatically corrects the set parameters (10).

[0077] The particle generation chamber (6.1) is raised (12) to a position that allows displacement of the feed material, which then displaces the coated feed material (1.1) (13). This displacement can be performed by any means, either manually or automatically.

[0078] On a semi-automatic workstation, four loosely rolled sheets of variable geometry are coated per minute.

Claims

1. 1. A method for applying a particle size controlled liquid coating to laminated sheets of various geometric shapes, comprising: (1) using as a feed material a continuous laminate strip and / or a single laminate sheet of variable geometry and / or a stacked laminate sheet pack of variable geometry; (2) selecting and positioning at least one mask to define a coating pattern according to the geometry of the resulting part or the geometry of the feed material; (3) setting operational parameters associated with the selected coating pattern defining mask; placing the supply material in a predetermined position to receive the coating (4); Providing (5) at least one particle generation chamber at a coating location; Pressurizing the particle generation chamber (6); and generating a particle size distribution of the suspended liquid coating (7); Measuring the particle size of the floating liquid coating (8); Determining whether the particle size of the liquid coating in suspension is within a set range (9); Modifying (10) the set particle size generation parameters of the floating liquid coating as required; Releasing pressure from the particle generation chamber to deposit the particles in suspension on any surface of the feed material via contact or other means (11); Positioning the particle generation chamber in a position that allows for displacement of the feed material (12); Moving the coating supply material (13); and The method includes:

2. 2. The method of claim 1, wherein the selection of the at least one coating pattern defining mask can be made from a plurality of masks having different geometric shapes.

3. 3. The method of claim 2, wherein the geometric shape of the covering pattern definition mask can be planar or can have a volume.

4. 3. The method of claim 2, wherein the selection of the at least one coating pattern definition mask can be performed manually.

5. 3. The method of claim 2, wherein the selection of the at least one coating pattern defining mask can be performed automatically.

6. 10. The method of claim 1, wherein the generation of suspended particles of the liquid coating occurs in a pressurized chamber.

7. The method of claim 6, wherein the pressurized chamber can have any geometric shape.

8. 7. The method of claim 6, wherein upon release of pressure from the pressurized chamber, the liquid coating particles are produced in suspension.

9. 7. The method of claim 6 further comprising measuring particle size of suspended liquid coating particles in the pressurized chamber.

10. 10. The method of claim 9, wherein the measurement generates a signal that is fed back to at least one control system to maintain the airborne particle size within a preset range.

11. 2. The method according to claim 1, characterized in that as coating a liquid substance can be used, such as an adhesive, an accelerator or initiator, an organic material, a metallic material, an insulating material, a thermal barrier or a resin.

12. The method of claim 11, wherein the liquid substance has a viscosity anywhere in the range of 100 to 3500 centipoise.

13. 2. The method of claim 1, which may include two or more stages of particle generation and application, using the same or different types of coating.

14. 1. An apparatus for applying particle size controlled liquid coatings to laminated sheets of various geometric shapes, comprising: At least one particle generation chamber (6.1); At least one covering pattern defining mask (2.1), At least one particle generator (6.2); At least one airborne particle size measuring device (8.1), At least one particle production chamber pressure regulating valve (6.3); At least one coating hatch (6.4); At least one control device (3.1) An apparatus comprising:

15. 15. The apparatus of claim 14, wherein the particle generation chamber comprises a confined pressurized space.

16. 16. The apparatus of claim 15, wherein the pressurized chamber can have any geometric shape.

17. 15. The apparatus of claim 14, wherein the generation of suspended particles of the liquid coating occurs in the particle generation chamber.

18. 20. The apparatus of claim 17, wherein said generating suspended particles of said liquid coating occurs when said particle generation chamber is pressurized.

19. 20. The apparatus of claim 18, wherein upon release of pressure from the pressurized chamber, the suspended particles of the liquid coating are deposited on any surface of the feed material.

20. 15. The apparatus of claim 14, wherein the particle size of the liquid coating is measured while suspended within the pressurized chamber.

21. 21. The apparatus of claim 20, wherein the measurements generate a signal that is fed back to at least one control system.

22. 22. The apparatus of claim 21, wherein a control system automatically modifies the operating parameters to maintain the airborne particle size within a preset range.

23. 15. The device according to claim 14, characterized in that as coating a liquid substance can be used, such as an adhesive, an accelerator or initiator, an organic material, a metallic material, an insulating material, a thermal barrier or a resin.

24. 24. The apparatus of claim 23, wherein the liquid substance has a viscosity anywhere in the range of 100 to 3500 centipoise.

25. 15. Apparatus according to claim 14, characterised in that it can be used in combination with a punch press.

26. 15. Apparatus according to claim 14, characterized in that it can be used to form a manual, semi-manual or automatic workstation.

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