Apparatus for manufacturing laminated core

Abstract

Disclosed is an apparatus for manufacturing a laminated core, which forms laminae for manufacturing a laminated core and couples the laminae to manufacture the laminated core. The apparatus for manufacturing a laminated core comprises: an elevatable blanking punch so as to sequentially form the laminae by blanking; and a stacking die which is provided below the blanking punch so that the laminae pass therethrough, and in which the laminae are coupled, wherein a lower end surface of the blanking punch has a protrusion portion for correcting warpage of the laminae in the stacking die. According to the present invention, warpage of laminae forming the laminated core can be minimized or prevented, thereby improving planarity, parallelism, and surface contour of the laminated core.

Description

Laminated core manufacturing equipment

[0001] The present invention relates to a laminated core manufacturing device, and more specifically, to a laminated core manufacturing device capable of correcting deformation (bending) of laminas forming a laminated core by changing the shape of a blanking punch.

[0002] In general, a laminated core refers to a core manufactured by integrating multiple thin plates, or laminas. For example, the laminated core can be formed by combining laminas sequentially formed by punching a metal strip within a laminated die.

[0003] These laminated cores are used as cores for various devices such as rotating machines such as generators and motors, transformers, and ignition systems, and various methods for manufacturing the laminated cores are known.

[0004] Known methods for manufacturing the above-described laminated core, i.e., methods for manufacturing the laminated core by laminating / integrating the above-described lamina, include a tab fixing method using continuous bonding of embossed protrusions (also called caulking protrusions), a welding fixing method using welding, for example, laser welding, and a rivet fixing method. Inventions related to the above-described tab fixing method are disclosed in Patent Registration No. 10-0762744, etc.

[0005] Another example of manufacturing the aforementioned laminated core is an adhesive fixing method that bonds the laminas with an adhesive. For example, Japanese Patent Laid-Open No. 2009-297758 discloses an invention in which an adhesive is applied to the surface of a metal strip supplied to a device (mold) for manufacturing a laminated core and the metal strip is punched out to manufacture the laminated core. Furthermore, a technology for manufacturing a laminated core by supplying a metal strip pre-coated with an adhesive to a mold is also disclosed.

[0006] Recently, a progressive die type laminated core manufacturing device has been used to manufacture the above-described laminated core. Fig. 1 is a drawing showing an example of a laminae and a laminated core, in which a plurality of laminae (L) are combined to form a laminated core (C). Of course, the shape of the laminae is not limited to the example of Fig. 1 and may vary.

[0007] Meanwhile, to improve the productivity of laminated cores, a double-row production method has recently been used, manufacturing laminated cores along multiple lines from a single metal strip. Both single-row and double-row production methods can degrade the quality of laminated cores due to deformation of the lamina within the lamination die.

[0008] The purpose of the present invention is to provide a laminated core manufacturing device that can minimize or prevent deformation of laminae formed by blanking due to lateral pressure within a laminated die by changing the shape of a blanking punch.

[0009] One aspect of the present invention provides a laminated core manufacturing device that forms laminas for manufacturing a laminated core and manufactures the laminated core by combining the laminas, comprising: a blanking punch that can be raised and lowered to sequentially form the laminas by blanking; a laminating die that is provided on a lower side of the blanking punch so that the laminas pass through and through which the laminas are combined; and a laminated core manufacturing device in which the lower surface of the blanking punch has a protrusion for correcting warpage of the laminas.

[0010] The above protrusion may form a surface with a concave middle portion on the lower surface of the blanking punch. The above protrusion may also form a wave-shaped curve on the lower surface of the blanking punch.

[0011] The above protrusion is formed at a portion facing the raised portion so as to press the raised portion formed in the laminae by the bending of the laminae. For example, the lower surface of the blanking punch may have a surface shape that is symmetrical with the bending shape of the laminae. In addition, a back pressure unit may be provided on the lower side of the laminae die to support the laminated core discharged from the laminae die.

[0012] According to the present invention, deformation (bending) of laminas forming a laminated core can be minimized or prevented by changing the shape of a blanking punch, so that the flatness, parallelism, and contour of the surface of the laminated core can be improved, and the press-in force deviation in a post-process such as a motor housing assembly process can be reduced, and the quality of the motor can be improved.

[0013] The features and advantages of the present invention may be better understood by reference to the following detailed description of embodiments of the present invention, together with the drawings, of which:

[0014] Fig. 1 is a perspective view showing an example of a laminar and a laminated core;

[0015] FIG. 2 is a schematic drawing showing one embodiment of a laminated core manufacturing device according to the present invention;

[0016] FIG. 3 is a schematic drawing showing another embodiment of a laminated core manufacturing device according to the present invention;

[0017] FIG. 4 is a drawing showing an example of a laminated die applicable to the laminated core manufacturing device illustrated in FIG. 2;

[0018] FIG. 5 is a drawing showing an example of a laminated die applicable to the laminated core manufacturing device illustrated in FIG. 3;

[0019] Figures 6 and 7 are drawings illustrating the shape of the bottom surface of a blanking punch corresponding to the deformation pattern of the lamina.

[0020] Hereinafter, preferred embodiments of the present invention, which can specifically realize the objectives of the present invention, will be described with reference to the attached drawings. In describing these embodiments, the same names and symbols will be used for identical components, and additional descriptions thereof will be omitted below.

[0021] The terms used herein are used to describe embodiments of the present invention and are not intended to limit the present invention. For example, terms related to numbers, such as "first" and "second," are used for convenience in describing embodiments of the present invention and do not define or limit the number of components included in the present invention.

[0022] And when it is said that a component is "connected" to another component, it should be understood that it may be directly connected to that other component, but it also includes an indirect connection, that is, a connection relationship in which another component exists in between.

[0023] In this specification, terms such as “include” or “have” should be understood to not exclude the possibility of adding features or components other than those described in the specification.

[0024] In addition, the present invention can be applied to manufacturing laminated cores using various methods, such as bonding (adhesive fixing) or tab fixing using embossing projections. The laminated core manufacturing device according to the present invention is a device that forms a plurality of laminas (L) by blanking and manufactures a laminated core by combining the laminas.

[0025] Referring to FIGS. 2 and 3, the laminated core manufacturing device includes a blanking punch (100) and a laminated die (200).

[0026] The blanking punch (100) is raised and lowered to sequentially form the laminae (L) by blanking, and the stacking die (200) is provided below the blanking punch (100) so that the laminae pass through. In the stacking die (200), the laminae are combined, and the stacking core is sequentially manufactured by combining the laminae.

[0027] The above-mentioned stacking die (200) is a hollow shape that is vertically perforated and is vertically perforated so that the laminae (L) pass through it in a stacked state. In addition, a back pressure unit (300) may be provided on the lower side of the stacking die. The back pressure unit (300) supports and lowers the stacking core (C) discharged from the stacking die (200).

[0028] The above back pressure unit (300) includes a back pressure plate (310) that is movably provided on the lower side of the laminated die (200), and the back pressure plate (310) rises to support the bottom of the laminated core and descends to extract the laminated core.

[0029] To be more specific, the backing plate (310) moves upward toward the stacking die (200) to support the bottom surface of the stacking core (C) discharged from the stacking die (200), i.e., the lowest lamina of the stacking core, and descends while supporting the stacking core (C). Then, after one stacking core is taken out, the backing plate (310) rises again to support the bottom of the next stacking core.

[0030] The above back pressure plate (310) is connected to a lifter (Lifter; 320) that elevates the back pressure plate (310). The lifter (320) is a component that elevates the back pressure plate (310).

[0031] The above lifter (320) may include, but is not limited to, a flexible cylinder such as a hydraulic or pneumatic cylinder, and various devices capable of raising and lowering the back pressure plate may be applied as the lifter (320).

[0032] And the backing plate (310) supports the laminated core (C) in the axial direction and descends together with the laminated core, and when the backing plate reaches the lower limit position (core extraction height), the laminated core can be extracted by a core extraction device (not shown) such as a pushing device or a conveyor. Thereafter, the backing plate (310) rises again to support the bottom surface of the laminated core discharged from the laminated die in the next order.

[0033] The basic function of the above-described backing unit (300) and the mechanism for extracting the laminated core are known techniques in the field of laminated core manufacturing. As in the embodiments of the present invention described below, the blanking punch (100) has a surface shape capable of correcting deformation, for example, warpage, of the laminas (L) forming the laminated core.

[0034] The embodiments illustrated in FIGS. 2 and 3 illustrate a progressive die including the blanking punch (100), the laminated die (200), and the back pressure unit (300). FIG. 2 illustrates an example of a progressive die for manufacturing a laminated core by a tab fixing method using embossing projections, and FIG. 3 illustrates an example of a progressive die for manufacturing a laminated core by adhesive method.

[0035] The above blanking punch (100) is provided on an upper die (10) that can be raised and lowered, and is raised and lowered together with the upper die (10). In addition, the above stacking die (200) is provided on a lower die (20) facing the upper die (10).

[0036] In this specification, the punching surface facing the metal strip is referred to as the lower surface of the blanking punch. In other words, the upper die (10) is provided so as to be able to move up and down on the upper side of the lower die (20), and in order to process the metal strip (S) intermittently transported between the upper die (10) and the lower die (20), at least one other punch may be added to the upper die (10) together with the blanking punch (100).

[0037] For example, a first punch (411) for processing a magnet hole and a second punch (412) for processing an axis hole may be provided on the upper mold (10).

[0038] In addition, a progressive mold for manufacturing a laminated core using a tab fixing method is provided with a third punch (413) for processing an embossing projection, as shown in the example in Fig. 2, and a fourth punch (414) for forming a hole at a position where an embossing projection is fitted for dividing between laminated cores.

[0039] A progressive mold for manufacturing a laminated core by adhesive method is equipped with an adhesive applicator (500), as in the example illustrated in FIG. 3, and an accelerator applicator (600) for promoting adhesive curing may be added. Of course, the adhesive applicator (500) and the accelerator applicator (600) may be replaced with a main agent applicator and a hardener applicator that apply a main agent and a hardener to one side and the opposite side of a metal strip, respectively.

[0040] The above-described lower die (20) is provided with dies (421, 422, 423, 424) corresponding to the first to fourth punches. Of course, the structure of the progressive mold for manufacturing the laminated core is not limited to the examples of FIGS. 2 and 3 and may be variously modified.

[0041] It is known in the art that the upper die may include a punch plate, a punch back plate and an upper holder and a struffer, and the lower die may include a die plate, a die back plate and a lower holder.

[0042] Referring to FIGS. 4 and 5, the laminated die (200) may have a hollow shape as described above, and may include a blanking die (210) for blanking and a guide mechanism provided below the blanking die (210) for aligning the laminae (L).

[0043] Therefore, each time the metal strip (S) is blanked, the laminae (L) inside the stacked die (200) are pushed and move downward by the thickness of the metal strip (S).

[0044] An example of the above guide mechanism is a squeeze mechanism (220; Squeezer), and the squeeze mechanism (220) has a structure that penetrates in the vertical direction so that the laminae (L) manufactured by blanking pass through in a forced-fit state (press-fit state).

[0045] More specifically, the squeeze mechanism (220) guides the stacking of the laminae (L) so that the laminae (L) are stacked in a coaxially aligned state under the blanking die, and the ring-shaped squeeze mechanism is also called a squeeze ring.

[0046] And, a guide mechanism called a pinch mechanism (230) may be provided in the lower region of the laminated die (200). The pinch mechanism (230) is configured to pass the laminated core (C) through the lower section of the laminated die (200), and may be provided on the lower side of the squeeze mechanism (220).

[0047] The pinch mechanism (230) may be a ring-shaped mechanism of the collet type that is elastically expandable and has restoring force to pressurize the circumference of the laminated core (C), or a block-type mechanism that pressurizes the outer circumference of the laminated core using the elastic force of a spring.

[0048] The pinch mechanism (230) forms a movement path for the laminated core (C) in the lower region of the laminated die (200), and is a mechanism that applies lateral pressure to hold the laminated core (C) with a predetermined force by pressing the periphery of the laminated core (C) formed by the combination of the laminae (L). Accordingly, the pinch mechanism (230) can prevent the laminated core discharged from the laminated die (200) from falling down before being supported by the back pressure plate (310).

[0049] Meanwhile, referring to FIG. 5, the laminated die (200) for the adhesive fixation method may include a heater (240) for thermally curing the adhesive between the laminas. In addition, an internal guide (250) for guiding the movement of the laminas (L) may be provided between the squeeze mechanism (220) and the pinch mechanism (230).

[0050] In the present embodiment, the heater (240) is provided in the area between the squeeze mechanism and the pinch mechanism (230), and the internal guide (250) has a cylindrical shape that penetrates vertically and guides the movement of the laminae within the heater (240). Of course, when the laminae are bonded by a room temperature curing adhesive, the heater (240) and the internal guide (250) may be omitted.

[0051] In FIGS. 4 and 5, the laminae (L) stacked vertically inside the laminated die (200) are separated based on solid lines, and the boundary indicated by the dotted lines represents the interface where the laminae are combined.

[0052] Meanwhile, the laminated die (200) applies lateral pressure by tightening the laminas (L) passing through the interior, and at this time, the lamina (L) may be deformed by the lateral pressure applied to the lamina.

[0053] In particular, in the case of a laminated core manufacturing device using a double-row production method, the remaining margin (residual width) at the edge of the blanking area after the blanking process is narrow, which adversely affects the circularity of the lamina formed in the blanking process, and various types of deformation may occur in the lamina, such as the central part of the lamina sagging downward or the lamina being bent into a wave shape due to lateral pressure applied from the laminated die.

[0054] And when the laminae are bonded by the heat curing method of the adhesive, the laminae may be heated unevenly and deformed within the laminating die (200), and if the curing temperature is lower than the appropriate temperature, the bonding between the laminae becomes unstable.

[0055] Additionally, when laminae are bonded using a room temperature curing method of the adhesive, deformation of the laminae may occur due to shrinkage of the adhesive.

[0056] The deformation of the above-described lamina also causes deformation of other laminas laminated on top, and adversely affects the flatness, parallelism, and contour of the surface of the laminated core.

[0057] To solve this problem, the lower surface of the blanking punch (100) facing the backing plate (310) has a protrusion (110) for correcting deformation of the laminae, for example, warping.

[0058] Referring to FIG. 6, the protrusion (110) can form a surface with a middle portion concave upward on the lower surface of the blanking punch (100) in accordance with the deformation pattern of the lamina illustrated in (a) of FIG. 6.

[0059] And, in accordance with the deformation pattern of the lamina illustrated in (a) of Fig. 7, the protrusion (110) may form a wave-shaped bend on the lower surface of the blanking punch (100). That is, as illustrated in (b) of Fig. 7, the lower surface of the blanking punch (100) may have a wave-shaped bend.

[0060] The deformation pattern of the lamina and the surface shape of the lower surface of the blanking punch corresponding thereto illustrated in FIGS. 6 and 7 are exemplary, so the deformation pattern of the lamina is not limited to the examples illustrated in FIGS. 6 and 7 and may be variously changed depending on the characteristics of the material (metal strip) or processing conditions, and the lower surface of the blanking punch is manufactured with a surface shape corresponding to the deformation pattern of the lamina.

[0061] According to embodiments of the present invention, the protrusion (110) is formed at a location corresponding to the protrusion (P) so as to locally pressurize the protrusion (P) formed in the laminas by the bending of the laminas. That is, the protrusion (110) is a configuration that applies pressure to the lamina to correct the bending of the lamina, thereby minimizing or preventing deformation of the lamina.

[0062] Specifically, the lower surface of the blanking punch (100) may have a surface shape opposite to the upper surface shape of the lamina in response to the bending pattern of the lamina. More specifically, the lower surface of the blanking punch (100) may have a surface shape that is symmetrical with the bending shape of the lamina.

[0063] As an example, in order to determine the shape of the bottom surface of the blanking punch (100), the warpage pattern of the lamina can be confirmed through a laminated core manufactured with a progressive mold to which a blanking punch (100) having a flat bottom surface and a backing plate (310) having a flat top surface are applied, and the shape of the bottom surface of the blanking punch can be determined according to the warpage pattern of the lamina generated in the mold.

[0064] For example, the lower surface of the blanking punch (100) may have a protrusion (110) facing a portion forming a convex portion, for example, a raised portion (P) on the upper surface of the lamina, and may have a groove (valley) facing a portion forming a concave portion (R) on the upper surface of the lamina.

[0065] Accordingly, when the metal strip is punched by the blanking punch (100), the blanking punch protrusion (110) can press the raised portion (P) forming portion of the lamina to correct (compensate) the warpage of the lamina.

[0066] As described above, preferred embodiments of the present invention have been described, and it is obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or scope thereof, in addition to the embodiments described above.

[0067] Therefore, the above-described embodiments should be considered as illustrative rather than restrictive, and accordingly, the present invention is not limited to the above description but may be modified within the scope of the appended claims and their equivalents.

[0068] The present invention relates to a laminated core manufacturing device, and can be used in the field of manufacturing laminated cores used in various devices including rotating machines such as motors.

Claims

1. A laminated core manufacturing device that forms laminas for manufacturing a laminated core and combines the laminas to manufacture the laminated core: A blanking punch capable of being lifted to sequentially form the above laminae by blanking; and A laminated die is provided on the lower side of the blanking punch so that the laminae pass through, and the laminae are combined; A laminated core manufacturing device having a lower surface of the blanking punch having a protrusion for correcting warpage of the laminae.

2. In paragraph 1, The above protrusion is a laminated core manufacturing device that forms a surface with a concave middle portion upward on the lower surface of the blanking punch.

3. In paragraph 1, The above protrusion is a laminated core manufacturing device that forms a wave-shaped curve on the lower surface of the blanking punch.

4. In paragraph 1, A laminated core manufacturing device in which the protrusion is formed at a portion facing the raised portion so as to press the raised portion formed in the laminae by the bending of the laminae.

5. In any one of paragraphs 2 to 4, A laminated core manufacturing device in which the lower surface of the above blanking punch is symmetrical with the bending shape of the above laminae.

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