Manufacturing Equipment and Method for Stacked Iron Cores

Abstract

The present invention provides a manufacturing apparatus and a manufacturing method for a laminated iron core. In order to ensure that an adhesive is accurately applied to an adhesive application surface, a guide member (100) is provided which guides the conveyance of a strip-shaped thin steel sheet (F) along the intermittent conveyance direction of the strip-shaped thin steel sheet (F) and restricts the upward movement of the strip-shaped thin steel sheet (F). An adhesive application device (50) is also provided which applies an adhesive to the adhesive application surface at a position corresponding to an iron core thin plate (A(W)).

Description

[0001] This application is a divisional application of the invention application with the application number "201780053427.X (International Application Number PCT / JP2017 / 000359)", the invention title of "Stacked Core Manufacturing Apparatus and Manufacturing Method", and the application date of January 9, 2017. Technical Field

[0002] The present invention relates to an apparatus and a method for manufacturing a stacked core, and more particularly to an apparatus and a method for manufacturing an adhesive-type stacked core formed by bonding a plurality of stacked core thin plates to each other with an adhesive. Background Art

[0003] As a stacked core used in a stator and a rotor of a rotating electric machine, an adhesive-type stacked core is known. The adhesive-type stacked core is formed as follows. That is, a core thin plate is blanked from a steel strip conveyed intermittently by a progressive die, the progressive die including a plurality of punching dies (die sets) each formed by a punch and a die, and the core thin plates are sequentially stacked in the die and bonded to each other with an adhesive such as an epoxy resin adhesive (Patent Documents 1 and 2).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-321850

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2009-124828 Summary of the Invention

[0008] Technical problem

[0009] Applying an adhesive to the adhesive application surface of each core thin plate (steel strip) needs to be accurately performed at a predetermined position on the adhesive application surface so as to obtain a bonding strength according to the design and prevent the adhesive from dripping to the outside, etc. In addition, it is required that the adhesive on the adhesive application surface does not spread or scatter to the surrounding environment due to vibrations of the core thin plate (steel strip) caused when the core thin plate moves.

[0010] The problem to be solved by the present invention is to accurately apply an adhesive to the adhesive application surface.

[0011] Solution to the problem

[0012] The manufacturing apparatus for a laminated iron core according to the present invention is a manufacturing apparatus for a laminated iron core, which is formed by laminating and bonding thin iron core plates. The thin iron core plates are formed by punching a steel strip into a predetermined shape. The manufacturing apparatus includes: an upper retainer and a lower retainer; a plurality of punches and dies, which are respectively provided on the upper retainer and the lower retainer, and the plurality of punches and dies sequentially punch out the thin iron core plates from the steel strip conveyed in an intermittent manner; a guiding member, which is provided on the lower retainer, and the guiding member guides the conveyance of the steel strip along the intermittent conveyance direction of the steel strip and restricts the upward movement of the steel strip; and an adhesive coating device, which is provided on at least one of the upper retainer and the lower retainer, and the adhesive coating device coats an adhesive on an adhesive coating surface at a portion of the steel strip corresponding to the thin iron core plate.

[0013] According to this configuration, the adhesive is coated on the adhesive coating surface in a state where the upward movement of the steel strip is restricted by the guiding member, and thus the adhesive is accurately coated on the adhesive coating surface.

[0014] In addition to the structure that restricts the upward movement of the steel strip by abutting against the steel strip, the guiding member further has a structure that restricts the movement of the steel strip in the left - right direction by abutting against the steel strip, and the guiding member guides the intermittent conveyance of the steel strip.

[0015] In this case, the adhesive is coated on the adhesive coating surface in a state where the movement of the steel strip in the left - right direction is restricted in addition to the upward direction, and thus the adhesive is coated on the adhesive coating surface in an even more accurate manner.

[0016] The manufacturing apparatus for a laminated iron core according to the present invention preferably further includes a guide pin, which is provided on the upper retainer and is configured to be inserted through a guide hole formed in the steel strip at each conveyance position to perform the positioning of the steel strip.

[0017] According to this configuration, the adhesive is coated on the adhesive coating surface in a state where the guide pin is inserted through the guide hole formed in the steel strip, and thus the adhesive is accurately coated on the adhesive coating surface.

[0018] The manufacturing apparatus for a laminated iron core according to the present invention preferably further includes a stripper plate, which is provided on the upper retainer so as to be displaceable in the vertical direction, and the stripper plate has a lower surface opposed to the upper surface of the die.

[0019] According to this configuration, the vertical movement of the steel strip can be restricted by the demolding template, so that the adhesive can be accurately applied to the adhesive application surface.

[0020] The manufacturing apparatus for a laminated core according to the present invention preferably further includes a demolding spring that biases the demolding template toward the lower retainer, and the demolding template is configured to press the steel strip against the upper surface of the mold by the spring force of the demolding spring.

[0021] According to this configuration, when the steel strip is about to press or is pressing against the mold by the demolding template, the adhesive can be applied to the adhesive application surface, and the adhesive can be accurately applied to the adhesive application surface.

[0022] In the manufacturing apparatus for a laminated core according to the present invention, the demolding template is preferably configured to press the steel strip against the upper surface of the mold until the punch is disengaged from the mold, and more preferably until the punch is disengaged from the steel strip.

[0023] According to this configuration, during the upward movement of the upper retainer after stamping, the state of pressing the steel strip against the upper surface of the mold by the demolding template is maintained until the punch is disengaged from the mold or until the punch is disengaged from the steel strip, thereby suppressing the swing of the steel strip during the upward movement of the upper retainer and suppressing the scattering of the adhesive applied to the steel strip.

[0024] In the manufacturing apparatus for a laminated core according to the present invention, the guide pin preferably includes a straight shaft portion, and the straight shaft portion is preferably positioned to project downward from the lower surface of the demolding template in a state where the demolding template is in the lowest position relative to the upper retainer by the biasing force of the demolding spring.

[0025] According to this configuration, during the downward movement of the upper retainer, the straight shaft portion of the guide pin enters the guide hole before the lower surface of the demolding template abuts against the steel strip, so that the positioning of the steel strip is smoothly performed without being hindered by the restriction of the demolding template on the steel strip.

[0026] The manufacturing apparatus for a laminated core according to the present invention preferably further includes a plurality of lifters provided on the lower retainer so as to be displaceable in the vertical direction, and the plurality of lifters separate the steel strip from the upper surface of the mold by abutting against the lower surface of the steel strip.

[0027] According to this configuration, the steel strip can be lifted from the upper surface of the mold when the steel strip is conveyed intermittently, so that even when the adhesive coating surface is the lower surface of the steel strip, the adhesive applied to the adhesive coating surface will not be rubbed by the upper surface of the mold.

[0028] The manufacturing apparatus for a laminated core according to the present invention preferably further includes: a plurality of lifters disposed on the lower retainer so as to be displaceable in the vertical direction, the plurality of lifters separating the steel strip from the upper surface of the mold by abutting against the lower surface of the steel strip; and a plurality of lifter springs that, when the stripping plate rises, upwardly urge the lifters to separate the steel strip from the upper surface of the mold in a case where the stripping plate abuts against the upper surface of the steel strip and the lifters abut against the lower surface of the steel strip.

[0029] According to this configuration, after the adhesive is applied, in a case where the core thin plate is vertically supported by the lifters and the stripping plate, the core thin plate returns to the lifted state (separated state), so that the swing of the steel strip during the lifting of the steel strip is suppressed, and the scattering of the adhesive applied to the steel strip is suppressed.

[0030] In the manufacturing apparatus for a laminated core according to the present invention, each of the lifters preferably serves as the guiding member.

[0031] According to this configuration, the number of components is reduced.

[0032] When the lifter also serves as the guiding member, the lifter only needs to be formed by respective lifter pins having circumferential grooves formed in the outer periphery of its upper portion, and has a structure such that the left and right edge portions of the steel strip enter the circumferential grooves. In this case, in a state where the steel strip is lifted by the lifter, the upward and downward movements of the steel strip are restricted according to the vertical width of the circumferential groove, and the flapping of the steel strip during intermittent conveyance is suppressed.

[0033] In the manufacturing apparatus for a laminated core according to the present invention, the adhesive coating apparatus is preferably a transfer type adhesive coating apparatus including a plurality of discharge holes that discharge the adhesive toward the adhesive coating surface to transfer the adhesive to each of a plurality of predetermined positions on the adhesive coating surface.

[0034] According to this configuration, the adhesive is accurately applied to the adhesive coating surface by transfer.

[0035] In the manufacturing apparatus for a laminated iron core according to the present invention, the adhesive coating apparatus preferably includes: an adhesive supply apparatus that supplies the adhesive to each of the discharge holes at a predetermined pressure; and a forward - retract drive apparatus that moves the discharge holes between a transfer position and a non - transfer position. In the transfer position, the adhesive can be transferred to the adhesive coating surface, and in the non - transfer position, the discharge holes cannot be retracted from the transfer position and the adhesive cannot be transferred.

[0036] According to this configuration, the transfer and non - transfer of the adhesive on the adhesive coating surface are selectively set only by selectively setting the position of the discharge holes to one of the transfer position and the non - transfer position.

[0037] The manufacturing apparatus for a laminated iron core according to the present invention is a manufacturing apparatus for a laminated iron core formed by laminating and bonding iron core thin plates. The iron core thin plates are formed by punching a steel strip into a predetermined shape. The manufacturing apparatus includes: an upper retainer and a lower retainer; a plurality of punches and dies disposed on the upper retainer and the lower retainer, the plurality of punches and dies sequentially punching out the iron core thin plates from the steel strip conveyed intermittently; guide pins disposed on the upper retainer, the guide pins being configured to be inserted through guide holes formed in the steel strip at each conveying position to perform positioning of the steel strip; a stripper plate disposed on the upper retainer so as to be displaceable in the vertical direction, the stripper plate having a lower surface opposed to the upper surface of the die; a stripper spring that biases the stripper plate toward the lower retainer; a plurality of lifters disposed on the lower retainer so as to be displaceable in the vertical direction, the plurality of lifters abutting against the lower surface of the steel strip; a plurality of lifter springs that, when the stripper plate rises, bias the lifters upward in a case where the stripper plate abuts against the upper surface of the steel strip and the lifters abut against the lower surface of the steel strip to lift the steel strip away from the upper surface of the die; and an adhesive coating apparatus disposed on at least one of the upper retainer and the lower retainer, the adhesive coating apparatus coating an adhesive on an adhesive coating surface at a portion of the steel strip corresponding to each iron core thin plate.

[0038] According to this configuration, the adhesive can be applied to the adhesive application surface in a state where the guide pin is inserted through the guide hole in the steel strip and when the steel strip is about to press or is pressing against the upper surface of the mold by the stripping plate, whereby the adhesive is accurately applied to the adhesive application surface. Further, after the adhesive is applied to the steel strip, the steel strip returns to the lifted state while being vertically supported by the lifter and the stripping plate, and thus, the sway of the steel strip during the lifting of the steel strip is suppressed, and the scattering of the adhesive applied to the steel strip is suppressed.

[0039] The method for manufacturing a laminated iron core according to the present invention is a method for manufacturing a laminated iron core formed by laminating and bonding iron core thin plates, the iron core thin plates being formed by blanking a steel strip into a predetermined shape using a stamping device including an upper retainer and a lower retainer, the manufacturing method including the following steps: a conveying step: conveying the steel strip in an intermittent manner while restricting upward movement of the steel strip by a guide member provided on the lower retainer and guiding the steel strip along an intermittent conveying direction; a stamping step: blanking an outer shape of the iron core thin plate by lowering the upper retainer using punches and dies provided on the upper retainer and the lower retainer; and an application step: applying an adhesive to an adhesive application surface of the steel strip using an adhesive application device provided on at least one of the upper retainer and the lower retainer before the stamping step.

[0040] According to this manufacturing method, the adhesive is applied to the adhesive application surface in a state where the intermittent conveyance of the steel strip is guided by the guide member and the upward movement of the steel strip is restricted by the guide member, and thus, the adhesive is accurately applied to the adhesive application surface.

[0041] In the method for manufacturing a laminated iron core according to the present invention, the conveying step preferably includes: conveying the steel strip in an intermittent manner in a lifted state where the steel strip is separated from the upper surface of a mold provided on the lower retainer by a lifter in a raised state of the upper retainer, the lifter being provided on the lower retainer so as to be vertically movable and being biased upward by a lifter spring.

[0042] According to this manufacturing method, even when the adhesive application surface is the lower surface of the steel strip, the adhesive applied to the adhesive application surface is not rubbed by the upper surface of the mold.

[0043] The method for manufacturing a laminated iron core according to the present invention preferably further includes a guiding insertion step: after completing the conveying step, during the descent of the upper retainer, a guide pin provided on the upper retainer is inserted into a guide hole formed in the steel strip.

[0044] According to this manufacturing method, the positioning of the steel strip is accurately performed, and thus the adhesive is accurately applied to the adhesive application surface.

[0045] The method for manufacturing a laminated iron core according to the present invention preferably further includes a pressing step: after completing the guiding insertion step, during the descent of the upper retainer, the steel strip is pressed against the upper surface of the die provided on the lower retainer by a stripping plate suspended on the upper retainer through a stripping spring.

[0046] According to this manufacturing method, after completing the guiding insertion step, the steel strip is pressed against the upper surface of the die. In other words, the guide pin is inserted into the guide hole in the steel strip before the steel strip is pressed against the upper surface of the die and restricted, so that the guide pin is smoothly inserted into the guide hole.

[0047] In the method for manufacturing a laminated iron core according to the present invention, the coating step preferably includes: applying the adhesive in a state where the guide pin is inserted into the guide hole, and when the steel strip is about to be pressed against or is being pressed against the upper surface of the die through the stripping plate along with the downward movement of the lifter; and after completing the application of the adhesive, by raising the upper retainer, in a state where the lifter abuts against the lower surface of the steel strip and the stripping plate abuts against the upper surface of the steel strip along with the upward movement of the lifter, returning the steel strip to the lifted state.

[0048] According to this manufacturing method, the adhesive is applied to the adhesive application surface when the steel strip is about to be pressed against or is being pressed against the die through the stripping plate, so that the adhesive is accurately applied to the adhesive application surface. In addition, the swaying of the steel strip during the ascent of the upper retainer is suppressed, and the scattering of the adhesive applied to the steel strip is suppressed.

[0049] The manufacturing method of the laminated iron core according to the present invention is a manufacturing method of a laminated iron core, the laminated iron core being formed by stacking and bonding iron core thin plates, the iron core thin plates being blanked from a steel strip into a predetermined shape by a stamping device including an upper retainer and a lower retainer, the manufacturing method including the following steps: a conveying step, in a raised state of the upper retainer, intermittently conveying the steel strip in a lifted state in which the steel strip is separated from the upper surface of a die provided on the lower retainer by a lifter, the lifter being provided on the lower retainer to be vertically movable and biased upward by a lifter spring; a guiding and inserting step, after completing the conveying step, during the descent of the upper retainer, inserting a guide pin provided on the upper retainer into a guide hole formed in the steel strip; a pressing step, after completing the guiding and inserting step, during the descent of the upper retainer, along with the downward movement of the lifter, pressing the steel strip against the upper surface of the die provided on the lower retainer by a stripping plate suspended on the upper retainer by a stripper spring; a stamping step, after completing the pressing step, by further lowering the upper retainer, at a plurality of pressing positions set in a row at intervals in the intermittent conveying direction, using a plurality of die sets each formed by a punch and a die provided on the upper retainer and the lower retainer, sequentially stamping the inner shape and the outer shape of each iron core thin plate; and a coating step, using an adhesive coating device set between the pressing position for blanking the inner shape and the pressing position for stamping the outer shape, arranged in a row with each pressing position and provided on at least one of the upper retainer and the lower retainer, coating an adhesive onto the adhesive coating surface of the steel strip, wherein the coating step includes: coating the adhesive in a state where the guide pin is inserted into the guide hole and when the steel strip is about to press against or is pressing against the upper surface of the die along with the downward movement of the lifter through the stripping plate; and after completing the coating of the adhesive, by raising the upper retainer, in a state where the lifter abuts against the lower surface of the steel strip and the stripping plate abuts against the upper surface of the steel strip along with the upward movement of the lifter, returning the steel strip to the lifted state.

[0050] According to this manufacturing method, with the guide pin inserted through the guide hole in the steel strip, and when the steel strip is about to press or is pressing the upper surface of the mold by the stripping plate, the adhesive is applied to the adhesive application surface, so that the adhesive is accurately applied to the adhesive application surface. In addition, after applying the adhesive, the steel strip is returned to the lifted state while being vertically supported by the lifter and the stripping plate, so that the sway of the steel strip during the lifting process of the steel strip is suppressed, and the dispersion of the adhesive applied to the steel strip is suppressed.

[0051] In the manufacturing method of the laminated core according to the present invention, the applying step preferably includes the steps of: transferring the adhesive to each of a plurality of predetermined positions on the adhesive application surface by discharging the adhesive from each of a plurality of discharge holes toward the adhesive application surface.

[0052] According to this manufacturing method, the adhesive is accurately applied to the adhesive application surface by transfer precisely.

[0053] In the manufacturing method of the laminated core according to the present invention, each core thin plate includes a plurality of tooth portions, and at least one of the application points is placed on the tooth portion.

[0054] According to this manufacturing method, in addition, bonding between adjacent core thin plates is performed in the tooth portions, and the laminated core with high bonding strength is produced.

[0055] Advantageous effects of the present invention

[0056] In the manufacturing apparatus and manufacturing method of the laminated core according to the present invention, the adhesive is accurately applied to the adhesive application surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a plan view showing an example of a core thin plate used in a stator of a stepping motor.

[0058] Figure 2 is shown in the manufacturing Figure 1 is an explanatory view of a strip layout in a progressive die machine used when manufacturing the core thin plate shown.

[0059] Figure 3 is a plan view of a core thin plate, schematically showing a core thin plate manufactured by the manufacturing apparatus and manufacturing method of the laminated core according to the present invention.

[0060] Figure 4 is shown in the manufacturing Figure 3Explanatory drawing of one embodiment of the tape layout in a progressive die machine used for the laminated core shown.

[0061] Figure 5 It is a schematic configuration drawing showing one embodiment of a manufacturing apparatus for a laminated core according to the present invention.

[0062] Figure 6 It is a cross-sectional view showing an adhesive device used in the manufacturing apparatus for a laminated core according to this embodiment.

[0063] Figure 7 It is an enlarged cross-sectional view of the main part of the adhesive device according to this embodiment.

[0064] Figure 8A It is a cross-sectional view of the internal shape stamping station of the manufacturing apparatus according to this embodiment in the top dead center state.

[0065] Figure 8B It is a cross-sectional view of the adhesive application station of the manufacturing apparatus according to this embodiment in the top dead center state.

[0066] Figure 9A It is a cross-sectional view of the internal shape stamping station of the manufacturing apparatus according to this embodiment during the descending process 1.

[0067] Figure 9B It is a cross-sectional view of the adhesive application station of the manufacturing apparatus according to this embodiment during the descending process 1.

[0068] Figure 10A It is a cross-sectional view of the internal shape stamping station of the manufacturing apparatus according to this embodiment during the descending process 2.

[0069] Figure 10B It is a cross-sectional view of the adhesive application station of the manufacturing apparatus according to this embodiment during the descending process 2.

[0070] Figure 11A It is a cross-sectional view of the internal shape stamping station of the manufacturing apparatus according to this embodiment during the descending process 3.

[0071] Figure 11B It is a cross-sectional view of the adhesive application station of the manufacturing apparatus according to this embodiment during the descending process 3.

[0072] Figure 12A It is a cross-sectional view of the internal shape stamping station of the manufacturing apparatus according to this embodiment in the bottom dead center state.

[0073] Figure 12Bis a cross-sectional view of the adhesive coating station of the manufacturing apparatus according to this embodiment in a bottom dead center state.

[0074] Figure 13A 1 is a cross-sectional view of an internal shape punching station of the manufacturing apparatus according to this embodiment in a rising process 1 .

[0075] Figure 13B 1 is a cross-sectional view of an adhesive coating station of the manufacturing apparatus according to this embodiment in a rising process 1 .

[0076] Figure 14A 2 is a cross-sectional view of an internal shape punching station of the manufacturing apparatus according to this embodiment in a rising process 2 .

[0077] Figure 14B 2 is a cross-sectional view of the adhesive coating station of the manufacturing apparatus according to this embodiment in the ascending process 2 .

[0078] Figure 15A FIG. 4 is a cross-sectional view of an internal shape punching station of the manufacturing apparatus according to this embodiment in a rising process 3 .

[0079] Figure 15B FIG. 3 is a cross-sectional view of the adhesive coating station of the manufacturing apparatus according to this embodiment in the ascending process 3 .

[0080] Figure 16 is an enlarged cross-sectional view of the lifting portion of the manufacturing apparatus according to the embodiment in a top dead center state.

[0081] Figure 17 2 is an enlarged cross-sectional view of the lifting portion of the manufacturing equipment according to this embodiment in a descending process 2 .

[0082] Figure 18 is an enlarged cross-sectional view of the lifting portion of the manufacturing apparatus according to the embodiment in a bottom dead center state.

[0083] Figure 19 1 is an enlarged cross-sectional view of the lifting portion of the manufacturing apparatus according to this embodiment in a lifting process 1 .

[0084] Figure 20 The picture is in manufacturing Figure 3 FIG. 1 is an explanatory diagram showing another embodiment of a belt layout in a progressive die machine used when laminating iron cores.

[0085] Figure 21 The picture is in manufacturing Figure 3 FIG. 1 is an explanatory diagram showing another embodiment of a belt layout in a progressive die machine used when laminating iron cores.

[0086] Figure 22A is a cross-sectional view of an internal shape punching station of a manufacturing apparatus according to another embodiment in a top dead center state.

[0087] Figure 22B is a cross-sectional view of an adhesive coating station of a manufacturing apparatus according to another embodiment in a top dead center state.

[0088] Reference Signs List

[0089] 10 Manufacturing Equipment

[0090] 12 Upper retainer

[0091] 13 through holes

[0092] 14 Lower retainer

[0093] 15 Spring chamber

[0094] 16 Back Panel

[0095] 17 Plug

[0096] 18 Punch Plate

[0097] 20 Punch for pilot hole punching

[0098] 22 Punches for internal shape stamping

[0099] 24 Punches for external shape stamping

[0100] 26 Ejector

[0101] 26A lower end

[0102] 26B upper flange

[0103] 26C shaft

[0104] 28 Demolder

[0105] 29 Stripper spring

[0106] 30 Stripper body

[0107] 32 Stripping plate

[0108] 33 lower surface

[0109] 34 Punch Insertion Hole

[0110] 36 Punch insertion hole

[0111] 38 Punch inserted into hole

[0112] 40 mold plate

[0113] 41 pin escape hole

[0114] 42 Die for via hole stamping

[0115] 44 Die for internal shape stamping

[0116] 46 Die for external shape stamping

[0117] 47 Upper surface

[0118] 48 Outlet hole

[0119] 50 Adhesive coating equipment

[0120] 52 Cam mechanism

[0121] 54 Driving equipment

[0122] 56 Holding hole

[0123] 58 Upper block

[0124] 59 Lower block

[0125] 60 Coating table

[0126] 61 Upper surface

[0127] 62 Adhesive accumulation part

[0128] 64 Discharge hole

[0129] 66 Internal block

[0130] 68 Adhesive supply channel

[0131] 70 Adhesive supply pipe

[0132] 72 Adhesive supply equipment

[0133] 74 Fixed cam

[0134] 74A Serrated protrusion

[0135] 74B Serrated recess

[0136] 76 Moving cam

[0137] 76A Serrated protrusion

[0138] 76B Serrated recess

[0139] 82 Stopper

[0140] 84 Guide pin

[0141] 84A Upper end flange

[0142] 84B Straight shaft part

[0143] Tapered shaft portion at the lower end of 84C

[0144] Mounting hole 86

[0145] Through hole 88

[0146] Through hole 90

[0147] Plug 92

[0148] Compression coil spring 94

[0149] Guide member 100

[0150] Lower surface 102

[0151] Side surface 103

[0152] Guide groove 104

[0153] Stopper surface 106

[0154] Guide pin guide hole 108

[0155] Lifter pin 110

[0156] Lifter pin hole 112

[0157] Lifter spring 114

[0158] Shoulder 116

[0159] Lifter pin 120

[0160] Step portion 120A

[0161] Lifter pin hole 122

[0162] Lifter spring 124

[0163] Circumferential groove 126

[0164] I Guide hole stamping station

[0165] II Internal shape stamping station[[ID=6,8]]

[0166] III Idle station

[0167] IV Adhesive coating station

[0168] V Idle station

[0169] VI External shape stamping station

[0170] VII Idle station

[0171] Predetermined interval T

[0172] Lifting amount L

[0173] A core thin plate

[0174] W core thin plate

[0175] M laminated core

[0176] F band (steel strip)

[0177] E coating point

[0178] E1 coating point

[0179] E2 coating point

[0180] G core thin plate group Detailed implementation manners

[0181] The preferred implementation manners according to the present invention will be described with reference to the accompanying drawings.

[0182] First, as a specific example of the laminated core, reference is made to Figure 1 the laminated core used in the stator of a stepping motor.

[0183] The laminated core is obtained by stacking a plurality of core thin plates A having the same shape. Each core thin plate A is obtained by blanking a steel strip or strip F into a predetermined shape by using a progressive die, and each core thin plate A includes an annular yoke portion B obtained by stamping the outer shape, a plurality of tooth portions (magnetic pole portions) C formed by stamping the inner shape and protruding radially inward from the yoke portion B, and a plurality of through holes D formed by stamping in the yoke portion B. Adjacent core thin plates A are bonded to each other by an adhesive of a plurality of coating points E1 and E2 applied to one surface (adhesive coating surface) of the yoke portion B and the tooth portion C in a dot shape.

[0184] The adhesive used here includes anaerobic adhesives (adhesive + hardening accelerator), one-component epoxy resin adhesives, two-component epoxy resin adhesives (first adhesive liquid + second adhesive liquid or main agent + initiator), thermosetting adhesives such as acrylic resin adhesives, moisture-curing adhesives, etc.

[0185] In Figure 1 it is noted that for ease of description, the coating points E1 and E2 are illustrated on the upper surface of the core thin plate A, but the coating points E1 and E2 are actually set on the lower surface of the core thin plate A so that the adhesive is applied to the lower surface (adhesive coating surface) of the core thin plate A.

[0186] As Figure 2As shown, in the order of intermittent conveyance of the strip F in a progressive die machine (manufacturing equipment for laminated cores), the steps of manufacturing a laminated core include preliminary stamping steps 1 to 5, an adhesive coating step 6, an external shape stamping step 7, a rotary stacking step 8, and a heating step 9.

[0187] In the preliminary stamping steps, stamping 1 of the pilot hole P, stamping 2 of the internal shape rough hole d1 and the through hole D, stamping 3 of the slot S1, stamping 4 of the internal shape d2, and stamping 5 of the cut S2 between the teeth and the tooth tip groove-shaped portion m are sequentially performed on the strip F by a die set (not shown). Each die set is formed by a punch and a die corresponding to the relevant stamping, thereby forming a basic shape except for the external shape stamping of the core thin plate A.

[0188] The adhesive coating step 6 is performed after the preliminary stamping steps 1 to 5. Adhesive is applied to the strip F at a plurality of coating points E1 set at positions corresponding to the slots S1 of the yoke portion B and coating points E2 set at two positions on each tooth portion C (in the form of Figure 1 the dots shown in detail). Here, a well-known anaerobic adhesive is used as the adhesive. Additionally, in Figure 2 order to facilitate description, the coating points E1 and E2 are shown on the upper surface side of the core thin plate A, but the coating points E1 and E2 are actually set on the lower surface side of the core thin plate A.

[0189] The external shape stamping step 7 is performed after the adhesive coating step 6. The external shape stamping step 7 is performed by a die set (not shown) formed by a punch and a die corresponding to the external shape d3 of the core thin plate A.

[0190] The rotary stacking step 8 is performed after the external shape stamping step 7. The die for the external shape stamping step 7 is a rotatable die, and it rotates a predetermined angle (for example, 90 degrees) around its central axis every time the external shape of one core thin plate A is stamped. As a result, while changing the position around the central axis, the core thin plates A stamped in the external shape stamping step 7 are sequentially stacked on the core thin plate group G that has been stamped and stacked in the rotatable die. Through this rotary stacking, the influence of possible minute thickness fluctuations existing in the core thin plates A can be eliminated, and the stacking height of the product (laminated core) can be managed with high precision. Then, the core thin plate group G is sequentially pushed into an extrusion ring (not shown) positioned below the rotatable die.

[0191] When the newly stamped core thin plate A is stacked on the core thin plate group G, the lower surface of the newly stamped core thin plate A is in close contact with the upper surface of the core thin plate A that is located in the uppermost layer of the core thin plate group G. As a result, the adhesive applied to the application points E1 and E2 in the shape of dots on the lower surface of the newly stamped core thin plate A is mixed with the curing accelerator previously applied to the upper surface of the core thin plate A that is located in the uppermost layer.

[0192] After the rotational stacking step 8 is completed, the heating step 9 is executed. A heating device (not shown) is provided in the lower part of the pressing ring, and the core thin plate group G is heated by the heating device while moving downward. Thereby, the adhesive between the core thin plates A is heated and cured, and thus the bonding strength can be improved. As the heating device for the adhesive described above, for example, a heater device that blows hot air onto the core thin plate group G can be used. After being heated by the heating device, the core thin plate group G is separated at the separation position of the core thin plates A, and thereby a laminated core M formed of a predetermined number of core thin plates A is obtained.

[0193] Next, Figure 4 and Figure 5 a description will be given of an embodiment of the manufacturing apparatus 10 for the laminated core. Note that in the following description, for the sake of simplicity of description, a simplified core thin plate W having an annular shape as Figure 3 shown will be described. Each core thin plate W is formed by stamping a circular inner shape IS and stamping a circular outer shape OS, and the adhesive is applied in a dot shape to the application points E set at a plurality of positions in the circumferential direction on the lower surface (adhesive application surface) of the annular portion R obtained by the stamping step.

[0194] The manufacturing apparatus 10 employs a progressive die system and sequentially includes a pilot hole stamping station I, an inner shape stamping station II, an idle station III, an adhesive application station IV, an idle station V, an outer shape stamping station VI, and an idle station VII in the progressive direction as Figure 4 and Figure 5 shown. The stations I, II, IV, and VI other than the idle stations III, V, and VII perform the respective steps in intermittent conveyance of the strip F in the progressive direction. Note that the portions to be stamped in the pilot hole stamping station I, the inner shape stamping station II, and the outer shape stamping station VI are indicated by diagonal lines. In the idle stations III, V, and VII, idle feeding of the strip F is performed.

[0195] The manufacturing apparatus 10 includes a plate-shaped upper retainer 12 fixed to the lower surface of an upper punch head (not shown) of a press, and includes a plate-shaped lower retainer 14 fixed to the upper surface of the lower worktable (not shown) of the same press so as to directly face the upper retainer 12.

[0196] The punches 20 for guide hole punching, the punches 22 for internal shape punching, and the punches 24 for external shape punching are attached to the lower side of the upper retainer 12 at positions corresponding to stations I, II, and VI through the back plate 16 and the punch plate 18.

[0197] The ejector 28 is supported by a suspension bolt (not shown) at a position below the upper retainer 12 so as to be displaceable in the vertical direction. The lowest position of the ejector 28 relative to the upper retainer 12 is set by the suspension support of the suspension bolt (not shown). The ejector 28 is formed as a combination of a plate-shaped ejector body 30 and an ejector plate 32, and the lower surface 33 of the ejector plate 32 directly faces the upper surface 47 (described below) of the die plate 40 and the dies 42, 44, and 46. In other words, the lower surface 33 of the ejector plate 32 directly faces the die plate 40 and the dies 42, 44, and 46. Punch insertion holes 34, 36, and 38 through which the upper surfaces 47 of the punches 20, 22, and 24 pass are formed in the ejector plate 32.

[0198] The plate-shaped die plate 40 is attached to the upper surface of the lower retainer 14. The dies 42 for guide hole punching, the dies 44 for internal shape punching, and the dies 46 for external shape punching are attached to the die plate 40 at positions corresponding to the punching stations I, II, and VI. The punch 20 for guide hole punching and the corresponding die 42 for guide hole punching, the punch 22 for internal shape punching and the die 44 for internal shape punching, and the punch 24 for external shape punching and the die 46 for external shape punching each correspond to each other and each form a die set.

[0199] Note that the upper surfaces of the die plate 40, the die 42, the die 44, and the die 46 are flush with each other, and thus these upper surfaces are hereinafter collectively referred to as the upper surface 47 of the die plate 40.

[0200] The adhesive application device 50 is provided in a portion of the die plate 40 corresponding to the adhesive application station IV. The adhesive application device 50 is vertically moved by a cam mechanism 52 driven by a drive device 54, and when in the raised position, applies (transfers) the adhesive to a plurality of portions (application points E) on the lower surface of the belt F. Except when forming the number of stacked core sheets W for separation to set the number of stacked core sheets W, each pressing operation applies the adhesive in a dot shape.

[0201] In the guide hole punching station I, each pressing operation, in other words, each intermittent conveyance of the belt F, punches the guide holes P (see Figure 4 ) in the belt F by the punch 20 for guide hole punching and the die 42 for guide hole punching. The guide holes P are formed near the edge portions on both sides (both the left and right sides) with respect to the direction (progressive direction) along which the belt F is intermittently conveyed.

[0202] In the internal shape stamping station II, each intermittent conveyance of the strip F stamps an internal shape IS in the strip F by a punch 22 for internal shape stamping and a die 44 for internal shape stamping (see Figure 4 ).

[0203] In the adhesive application station IV, an adhesive is applied in dot form to an application point E on the lower surface of the strip F by an adhesive application device 50 in a raised position. Note that when forming the number of stacks of the core sheets W for separation (which occurs every predetermined number of intermittent conveyances) for setting the number of stacks of the core sheets W, the adhesive application device 50 descends to a lowered position, thus pausing the application of the adhesive to the strip F.

[0204] In the external shape stamping station VI, an external shape OS is stamped in the strip F by a punch 24 for external shape stamping and a die 46 for external shape stamping (see Figure 4 ). This stamping provides a complete core sheet W. The produced core sheets W descend and are sequentially stacked in the die 46 for external shape stamping. Among the core sheets W stacked in the die 46 for external shape stamping, except for the core sheets W for separation to which no adhesive is applied, the vertically adjacent core sheets W are bonded to each other by the adhesive applied to the application point E.

[0205] In the external shape stamping station VI, the stack of core sheets W is taken out downward from an outlet hole 48 formed in the lower retainer 14 and is taken to a post-treatment step for thermally curing the adhesive as needed.

[0206] Next, details of the adhesive application device 50 are described with reference to Figure 6 and Figure 7 .

[0207] The adhesive application device 50 is a transfer type adhesive application device and includes an application table 60, and the application table 60 is implemented as a connecting body formed by an upper block 58 and a lower block 59. The application table 60 is vertically movably inserted through a holding hole 56 formed in the lower retainer 14 and the die plate 40.

[0208] A cam mechanism 52 is provided below the application table 60. The cam mechanism 52 includes: a fixed cam 74 formed by a plate cam fixed to the bottom of the lower block 59; and a moving cam 76 formed by a plate cam movably provided on the bottom of the lower block 59. The moving cam 76 is connected to a drive device 54, and when at Figure 6During the observation, it is reciprocally driven in the left - right direction by the driving device 54. The fixed cam 74 includes a serrated portion having serrated protrusions 74A and serrated recesses 74B alternately arranged in the left - right direction on its lower surface, and the moving cam 76 includes a serrated portion having serrated protrusions 76A and serrated recesses 76B alternately arranged on its upper surface.

[0209] As shown in the figure, when the moving cam 76 is in the position where the serrated protrusion 74A of the fixed cam 74 and the serrated protrusion 76A of the moving cam 76 are aligned with each other, the coating table 60 is placed in the raised position (transfer position). In the raised position, the upper surface 61 of the upper block 58 is located below the upper surface 47 of the mold plate 40 with a height difference α.

[0210] When the moving cam 76 is driven leftward by the driving device 54 (during the observation in Figure 6 ), and the moving cam 76 is placed in the position where the serrated recess 74B of the fixed cam 74 and the serrated protrusion 76A of the moving cam 76 are aligned with each other, the coating table 60 and the fixed cam 74 descend (retract downward), and the coating table 60 is placed in the lowered position. In the lowered position (non - transfer position), the upper surface 61 of the upper block 58 is placed below the upper surface 47 of the mold plate 40 with a larger height difference greater than the height difference α.

[0211] The upper block 58 is provided with: an adhesive accumulation portion 62 formed by an annular groove; and a plurality of discharge holes 64 each extending in the up - down direction (vertical direction) from the adhesive accumulation portion 62 to the horizontal upper surface 61 of the upper block 58 and opening in the upper surface 61. The discharge holes 64 are placed at positions corresponding to the coating points E of the tape F (core thin plate W) located at the adhesive coating station IV.

[0212] The inner block 66 is attached to the upper block 58. The inner block 66 and the lower block 59 form an adhesive supply passage 68 for supplying the adhesive to the adhesive accumulation portion 62. The flexible adhesive supply tube 70 is connected to each adhesive supply passage 68. The adhesive supply tube 70 is connected to the adhesive supply device 72. The adhesive supply device 72 pressurizes the adhesive to a predetermined pressure, measures the pressurized adhesive, and supplies the pressurized adhesive to the adhesive accumulation portion 62 at a predetermined flow rate via the adhesive supply tube 70 and the adhesive supply passage 68. Thus, the adhesive is constantly supplied from the adhesive accumulation portion 62 to the discharge holes 64 at a predetermined pressure.

[0213] Note that in this embodiment, two adhesive supply tubes 70 and two adhesive supply channels 68 are provided, and the adhesive is supplied to two portions of the adhesive accumulation portion 62 that are separated from each other by 180 degrees in the circumferential direction, but this configuration is not necessary. The number and supply position only need to be the number and supply position necessary to ensure the supply amount of the adhesive so as to maintain the adhesive pressure in the entire area of the adhesive accumulation portion 62 at a predetermined pressure. The appropriate pressure of the adhesive is determined according to the size and number of the discharge holes 64, the arrangement of the discharge holes 64, and the like.

[0214] The adhesive in the adhesive accumulation portion 62 is discharged from the discharge holes 64 to a position above the coating table 60. Since the pressure of the adhesive in the adhesive accumulation portion 62 is maintained at a predetermined value and the adhesive has a predetermined viscosity, the adhesive discharged to the outside from the discharge holes 64 constantly forms a protruding portion N, and the protruding portion N protrudes above the upper surface 61 of the upper block 58 in a substantially hemispherical shape as Figure 7 shown. The height of the protruding portion N is slightly larger than the height difference α. Therefore, when the coating table 60 is in the raised position (transfer position) and the belt F descends to the contact position where the lower surface of the belt F contacts the upper surface 47 of the mold plate 40, the protruding portion N of the adhesive of each discharge hole 64 contacts the lower surface of the belt F, and the adhesive is transferred to the coating point E in a dot shape.

[0215] If the adhesive coating device 50 intermittently forms the protruding portion N, the timing is set such that the protruding portion N is formed when the belt F is placed in the contact position where the lower surface of the belt F contacts the upper surface 47 of the mold plate 40. As a result, in a state where the lower surface of the belt F is in contact with the upper surface 47 of the mold plate 40, the adhesive is transferred to the coating point E in a dot shape.

[0216] The transfer amount of the adhesive at the coating point E can be controlled according to the height difference α and the size (volume) of the protruding portion N. The size of the protruding portion N is quantitatively determined according to the pressure of the adhesive in the adhesive accumulation portion 62, the viscosity of the adhesive, the inner diameter of the discharge hole 64, etc., so the transfer amount of the adhesive at the coating point E can be set to an optimal value by optimally setting these factors.

[0217] When performing transfer coating of the adhesive using the discharge holes 64 as described above, the minimum distance between the coating points E can be set to a size slightly larger than the inner diameter of the discharge holes 64 by reducing the distance between adjacent discharge holes 64. As a result, even when the tooth portion C is small, the coating points E can be set in a plurality of portions of the tooth portion C. This helps to enhance the bonding strength of the tooth portion C in the laminated bonding of a plurality of core thin plates W.

[0218] When the coating table 60 is in the lowered position (non-transfer position), the upper surface 61 of the upper block 58 is placed below the upper surface 47 of the die plate 40 with a larger height difference greater than the height difference α. As a result, the protruding portion N of the adhesive with a defined size does not contact the lower surface of the tape F, and the adhesive is not transferred to the lower surface of the tape F. Therefore, the coating table 60 only needs to be moved to the lowered position when forming the core thin plates for separation to set the stacking number of the core thin plates W.

[0219] As Figure 8A and Figure 8B shown, the ejector 26 is attached to the upper retainer 12. It should be noted that Figure 8A the figure shows the internal shape stamping station II as a representative example of the stamping station, while Figure 8B the figure shows the adhesive coating station IV.

[0220] Each ejector 26 includes: a lower end 26A that abuts against the upper part of the ejector body 30; a shaft portion 26C that is vertically movably assembled in a through hole 13 formed in the upper retainer 12; and an upper end flange 26B that is located in a spring chamber 15 formed in the upper retainer 12. The upper part of the spring chamber 15 is closed by a plug 17 fixed to the upper retainer 12. An ejector spring 29 (ejector spring) composed of a compression coil spring is provided between the plug 17 and the upper end flange 26B. The ejector spring 29 applies a downward force to the ejector 26.

[0221] As Figure 12A and Figure 12B shown, the lowest position (bottom dead center position) of the upper retainer 12 is determined by bringing the lower surface of the upper retainer 12 into contact with the upper surfaces of the stoppers 82 provided on both the left and right sides of the lower retainer 14 at the bottom dead center of the upper punch (not shown) of the press. When the upper retainer 12 is placed in the lowest position, the stripper plate 32 contacts the tape F and presses the tape F against the upper surface 47 of the die plate 40 while being displaced relative to the upper retainer 12, resulting in the compressive deformation of the ejector spring 29.

[0222] The relative displacement stroke of the ejector 28 relative to the upper retainer 12 in the vertical direction is greater than the penetration stroke of the punches 20, 22, and 24 relative to the dies 42, 44, and 46. As Figure 12A shown, the penetration stroke is the stroke corresponding to the penetration amount of the punches 20, 22, and 24 into the dies 42, 44, and 46 in a state where the upper retainer 12 is in the lowest position.

[0223] That is, the ejector 28 including the stripping plate 32 is formed such that the stroke between the lowest position of the ejector 28 relative to the upper retainer 12 and the position where the ejector 28 presses the tape F against the upper surface 47 of the die plate 40 of the lower retainer 14 after moving relative to the upper retainer 12, causing elastic deformation of the ejector spring 29, is greater than the maximum entry stroke of the punches 20, 22, and 24 into the dies 42, 44, and 46.

[0224] Due to this stroke setting, during the upward movement of the upper retainer 12 after stamping, the punches 20, 22, and 24 are pulled out from the dies 42, 44, and 46 and the tape F. Thereafter, the ejector 28 rises together with the upper retainer 12 and the pressing of the ejector 28 against the tape F is released. As a result, the state of pressing the tape F against the upper surface 47 of the die plate 40 by the ejector 28 is maintained until the punches 20, 22, and 24 are disengaged from the dies 42, 44, and 46.

[0225] As Figure 8A shown, in stations II to VII other than the guide hole punching station I, guide pins 84 that can enter the guide holes P in the tape F are provided in each of stations II to VII. Note that Figure 8B the description of the guide pin 84 provided in the adhesive application station IV is omitted.

[0226] Each guide pin 84 sequentially includes an upper end flange 84A, a straight shaft portion 84B, and a lower end tapered shaft portion 84C in the axial direction. Each guide pin 84 is inserted into a mounting hole 86 formed in the upper retainer 12 and vertically passes through a through hole 88 formed in the back plate 16 and the punch plate 18 and a through hole 90 formed in the ejector 28 in a slidable manner. The lower portion of the straight shaft portion 84B and the lower end tapered shaft portion 84C project downward from the lower surface 33 of the stripping plate 32 in the lowest position relative to the upper retainer.

[0227] Due to the above setting, during the downward movement of the upper retainer 12, the straight shaft portion 84B of the guide pin 84 enters the corresponding guide hole P before the lower surface 33 of the stripping plate 32 abuts against the tape F, thereby positioning the tape F in the progressive direction and in the direction orthogonal to the progressive direction (that is, in the left - right direction) on the upper surface 47 of the die plate 40.

[0228] The lowest position (lower limit position) of each guide pin 84 is set by bringing the lower surface of the upper end flange 84A into contact with the upper surface of the back plate 16 (the bottom surface forming the mounting hole 86). Each guide pin 84 is urged downward by the spring force of a compression coil spring 94 provided between the plug 92 and the upper end flange 84A, and the plug 92 is fixed to the upper retainer 12 to close the upper portion of the mounting hole 86. The spring urging structure is an escape structure that prevents damage to the guide pin 84 when the guide pin 84 does not properly enter the guide hole P. Note that the die plate 40 is provided with a pin escape hole 41 for the guide pin 84 to enter.

[0229] Next, refer to Figure 4 , Figure 8A and Figure 8B to describe the supply guiding structure and lifting structure of the tape F. On the lower retainer 14, that is, on the die plate 40 fixed to the lower retainer 14 in the illustrated embodiment, left and right guiding members 100 for guiding the conveyance of the tape F (thin steel plate) are symmetrically attached in a direction along the direction in which the tape F is intermittently conveyed (progressive direction). The left and right guiding members 100 each have a strip shape that is long in the progressive direction of the tape F, and as Figure 4 shown, are provided at intervals in the progressive direction of the tape F (except in regions corresponding to stations II, IV, and VI).

[0230] As Figure 16 shown, each of the left and right guiding members 100 has: a lower surface 102 formed by a horizontal wall that faces the upper surface 47 of the die plate 40 from above and has a predetermined distance T from the upper surface 47; and side surfaces 103 formed by vertical walls that face the left or right end surface of the tape F, with a predetermined gap therebetween, such that the opposing side walls of the left and right guiding members 100 have a hook-shaped cross-sectional shape. The lower surface 102 and side surfaces 103 of the guiding member 100 and the upper surface 47 of the die plate 40 cooperate with each other to define left and right guiding grooves 104 that extend in the progressive direction of the tape F and have a rectangular cross-sectional shape with an inward-facing opening.

[0231] The left and right edge portions of the tape F enter the left and right guiding grooves 104, respectively. As a result, the guiding member 100 guides the intermittent conveyance of the tape F by restricting the movement of the tape F in the left-right direction using the side surfaces 103 and restricting the upward movement of the tape F using the lower surface 102.

[0232] Therefore, when the belt F is conveyed intermittently, displacement of the belt F in the left-right direction and the vertical direction is suppressed, and when the adhesive is applied to the adhesive application surface (lower surface) of the belt F, movement of the belt F in the left-right direction and the upward direction relative to the upper surface 47 of the die plate 40 is restricted. As a result, the adhesive is accurately applied to the adhesive application surface. Note that downward movement of the belt F is restricted (prevented) by being placed on the upper surface 47 of the die plate 40 or by being lifted by the lifter pins 110 described below.

[0233] The above-described predetermined distance T is greater than the sum of the lift amount L of the belt F by the lifter pins 110 described below and the thickness of the belt F. With this setting, even when the belt F is lifted by the lifter pins 110, the belt F does not come into contact with the lower surface 102 of the guide member 100. As a result, when the belt F is conveyed intermittently, the upper surface of the belt F does not slide in contact with the lower surface 102 of the guide member 100, and when the belt F is conveyed intermittently, the guide member 100 does not increase the frictional resistance.

[0234] As Figure 4 shown, the lifter pins 110 are provided at predetermined intervals in the progressive direction of the belt F on both the left and right sides of the die plate  40. In a plan view, the arrangement positions of the lifter pins 110 overlap the arrangement positions of the guide member 100.

[0235] As Figure 8A and Figure 8B shown, the lifter pins 110 are provided in lifter pin holes 112 so as to be displaceable in the vertical direction. The lifter pin holes 112 are formed in the die plate 40 and the lower retainer 14 and open in the upper surface 47 of the die plate 40. The upper end side of each lifter pin 110 is exposed on the upper surface 47 of the die plate 40. Lifter springs 114 each composed of a compression coil spring are provided between the lifter pins 110 and the bottoms of the lifter pin holes 112. The lifter springs 114 apply an upward force to the corresponding lifter pins 110.

[0236] Approximately half of the upper end surface of each lifter pin 110 may come into contact with the lower surface of the belt F, and the other half may come into contact with a stopper surface 106 formed on each guide member 100. As a result, as Figure 8A , Figure 8B and Figure 16 shown, when the belt F is not pressed down by the ejector 28, the lifter pins 110 are placed in a raised position where the upper end surface is in contact with the stopper surface 106 by the spring force of the lifter springs 114, and lift (raise) the belt F from the upper surface 47 of the die plate 40. When the belt F is pressed down by the ejector 28, as Figure 11A , Figure 11B and Figure 18As shown, the lifter pin 110 is lowered by the belt F against the spring force of the lifter spring 114 and is fully sunk into the lifter pin hole 112.

[0237] As Figure 16 shown, the lifting amount L of the lifter pin 110 with respect to the belt F is determined by bringing the upper surface of the lifter pin 110 into contact with the downward-facing stopper surface 106 of the guide member 100, and the lifting amount L is set to a value greater than the coating thickness (maximum thickness) of the adhesive transferred to the lower surface of the belt F.

[0238] Next, referring to Figure 8A 、 Figures 8B to 15A 、 Figure 15B and Figures 16 to 19 , the operation of the manufacturing apparatus 10 with the above configuration is described. Note that Figures 8A to 15A illustrates the operation of the internal shape stamping station II as a representative example of the stamping station, while Figures 8B to 15B illustrates the operation of the adhesive coating station IV. The operations of the pilot hole stamping station I and the external shape stamping station VI are substantially the same as those of the internal shape stamping station II, and thus the description of the operations is omitted.

[0239] Figure 8A and Figure 8B illustrate a state in which the upper ram (not shown) of the press is at the top dead center and the upper retainer 12 is at the highest raised position (top dead center position) as a pressing start state. In this pressing start state, the punch 22, the stripper 28, and the guide pin 84 for internal shape stamping are in positions separated from the die plate 40 in the upward direction. The belt F is in the raised position (lifted state) in which the belt F is separated from the upper surface 47 of the die plate 40 by the lifter pin 110 (see Figure 16 ). In the lifted state, the belt F is intermittently conveyed in the progressive direction by an intermittent feeding device (not shown) (a predetermined amount is conveyed each time of intermittent conveyance), and the lower surface of the belt F does not slide in contact with the upper surface 47 of the die plate 40.

[0240] When one intermittent conveyance is completed or during the intermittent conveyance, the upper retainer 12 starts to descend from the top dead center position, as Figure 9A and Figure 9B shown. As the upper retainer 12 descends, before the stripper 28 presses the belt F against the upper surface 47 of the die plate 40, first the tapered shaft portion 84C and then the straight shaft portion 84B of the lower end of the guide pin 84 enter the guide hole P in the belt F, as Figure 10A and Figure 10B shown. As a result, positioning of the belt F with respect to the manufacturing apparatus 10 is performed in the conveyance direction (progressive direction) and the left - right direction.

[0241] Positioning is performed in a state where the tape F is lifted from the upper surface 47 of the mold plate 40, and thus the tape F is moved in the conveying direction and the left - right direction with low frictional resistance to be positioned relative to the manufacturing apparatus 10.

[0242] As Figure 11A and Figure 11B shown, as the upper retainer 12 further descends, the lower surface 33 of the stripper plate 32 abuts against the upper surface of the tape F (see Figure 17 ), and the ejector 28 overcomes the spring force of the lifter spring 114 and pushes the tape F downward together with the lifter pin 110 to a position where the tape F abuts against the upper surface 47 of the mold plate 40 (see Figure 18 ). Note that at this time, in view of the overall setting of the spring forces of the ejector spring 29 and the lifter spring 114, the ejector spring 29 does not compress and deform, and the ejector 28 remains in the lowest position relative to the upper retainer 12.

[0243] As Figure 12A and Figure 12B shown, as the upper retainer 12 further descends, the ejector spring 29 compresses and deforms, the upper retainer 12 descends relative to the ejector 28, and the lower surface of the upper retainer 12 abuts against the upper surface of the stopper 82 at the bottom dead center. As a result, as Figure 12A shown, in the internal shape stamping station II, the punch 22 for internal shape stamping enters the mold 44 for internal shape stamping in a state where the tape F is in a clamped state of being pressed against the upper surface 47 of the mold plate 40 by the spring - biased ejector 28, and the stamping of the internal shape IS is performed. Also, in the adhesive coating station IV, when the tape F is pressed against the upper surface 47 of the mold plate 40 by the spring - biased ejector 28, the protrusion N of the adhesive discharged from the discharge hole 64 is transferred to the corresponding coating point E on the lower surface of the tape F (see Figure 7 ).

[0244] The transfer of the adhesive is performed by the guide member 100 in a state of restricting the movement of the tape F in the left - right direction and restricting the upward movement of the tape F, and the positioning of the tape F is performed by the guide pin 84. Therefore, even when the coating point E is small, the adhesive is accurately transferred to the coating point E with high positional accuracy.

[0245] In addition, the transfer of the adhesive is performed while the lower surface of the tape F is pressed against the upper surface 47 of the die plate 40 so that the tape F cannot vibrate. Therefore, even when the stamping of the internal shape IS and the transfer of the adhesive are performed simultaneously, the transfer of the adhesive can be performed without vibration of the hoop material F caused by the stamping impact in the internal shape stamping station II, and the adhesive is accurately transferred to the application point E. This also helps to allow the adhesive to be accurately transferred to the application point E with high positional accuracy even when the application point E is small.

[0246] As Figure 13A and Figure 13B shown, when the stamping of the internal shape IS and the transfer of the adhesive are completed, the upper retainer 12 starts to rise from the bottom dead center. When the upper retainer 12 rises from the bottom dead center, the punch 22 for internal shape stamping first disengages from the die 44 for internal shape stamping in the upward direction. As described above, the stroke of the ejector 28 moving relative to the upper retainer 12 is greater than the maximum entry stroke of the punch 22 for internal shape stamping into the die 44 for internal shape stamping. Therefore, the state of pressing the tape F against the upper surface 47 of the die plate 40 by the ejector 28 is maintained until the punch 22 for internal shape stamping disengages from the die 44 for internal shape stamping.

[0247] As a result, even when vibration occurs due to friction when the punch 22 for internal shape stamping disengages from the die 44 for internal shape stamping and the stamping opening in the tape F, the vibration is not transmitted to the portion of the tape F located in the adhesive application station IV, so that the transfer shape of the adhesive transferred to the application point E on the hoop material F does not become distorted or the adhesive does not spread.

[0248] As Figure 14A and Figure 14B shown, as the upper retainer 12 rises, the ejector 28 rises together with the upper retainer 12, the lifter pin 110 rises by the spring force of the lifter spring 114, and the tape F is lifted. The lifter pin 110 abuts against the stopper surface 106, so that the tape F returns to the raised position (lifted state) separated from the upper surface 47 of the die plate 40.

[0249] As Figure 19 shown, the rising of the tape F is performed while preventing the tape F from shifting in the left and right directions by the guide member 100. The ejector 28 abuts against the upper surface of the tape F, the lifter pin 110 abuts against the lower surface of the tape F, and the tape F is vertically supported by the ejector 28 and the lifter pin 110. Therefore, the swaying of the tape F during the rising process is suppressed. As a result, during the rising process (lifting process) of the tape F, the transfer shape of the adhesive transferred to the application point E on the tape F is prevented from becoming distorted or the adhesive is prevented from spreading.

[0250] AsFigure 15A and Figure 15B As shown, as the upward movement of the upper retainer 12 further proceeds, the guide pin 84 disengages from the guide hole P in the upward direction. Then, the upper retainer 12 returns to Figure 8A and Figure 8B the top dead center position shown in. The intermittent conveyance of the belt F starts at the time point when the guide pin 84 disengages from the guide hole P. The intermittent conveyance is performed in a state where the belt F is lifted by the lifter pin 110 and the lower surface is separated from the upper surface 47 of the die plate 40 by the lifting amount L (see Figure 16 ). Therefore, the adhesive transferred to the coating point E on the lower surface of the belt F is not rubbed by the upper surface 47 of the die plate 40.

[0251] The intermittent conveyance is performed in a state where the upward movement of the belt F is restricted by the guide member 100 and the lateral displacement of the belt F is restricted. Therefore, during the conveyance of the belt F, the transfer shape of the adhesive transferred to the coating point E on the belt F does not become distorted or the adhesive does not spread. The intermittent conveyance is completed before the start of the next stamping step.

[0252] Through the above, the adhesive is accurately applied to the adhesive application surface of each core thin plate W. In addition, the adhesive applied to the adhesive application surface of each core thin plate W does not diffuse into the surrounding environment and the transfer shape does not become distorted or the adhesive does not spread. Thus, even when the size of the laminated core is small, a high-quality laminated core can be stably produced.

[0253] As another embodiment, as shown in Figure 20 , the guide hole P may be formed in a position corresponding to a place directly below the guide pin guide hole 108 formed in the guide member 100 and passing therethrough. In this case, the guide pin 84 is accurately inserted into the guide hole P in a state where the flapping of the belt F is suppressed. In addition, each guide pin 84 (see Figure 8A ) passes through the guide pin guide hole 108 and enters the guide hole P, thus enhancing the positioning accuracy of the guide pin 84 with respect to the belt F.

[0254] Next, another embodiment of the laminated core manufacturing apparatus 10 will be described with reference to Figure 21 , Figure 22A and Figure 22B . Note that in Figure 21 , Figure 22A and Figure 22B , the parts corresponding to those shown in Figure 4 , Figure 8A and Figure 8B are denoted by the same reference numerals as those in Figure 4 , Figure 8A and Figure 8B , and their descriptions are omitted.

[0255] In this embodiment, as Figure 21 shown, the guide member 100 is omitted, and the lifter pin 120 also serves as a guide member for the tape F. The lifter pins 120 are provided on both the left and right sides of the die plate 40, and a predetermined interval is provided between the lifter pins 120 in the progressive direction of the tape F.

[0256] As Figure 22A and Figure 22B shown, the lifter pins 120 are provided in the lifter pin holes 122 so as to be displaceable in the vertical direction, and the upper end portions thereof project from the upper surface 47 of the die plate 40. The lifter pin holes 122 are formed in the die plate 40 and the lower retainer 14 and open in the upper surface 47 of the die plate 40. Lifter springs 124 each constituted by a compression coil spring are provided between the bottom of the lifter pins 120 and the lifter pin holes 122. The lifter springs 124 apply an upward force to the corresponding lifter pins 120. When the tape F is not pressed down by the stripper 28, each lifter pin 120 is placed in the raised position, in which the step portion 120A abuts against the shoulder portion 116 by the spring force of the lifter spring 124, and the shoulder portion 116 is provided at the joint between the die plate 40 and the lower retainer 14; and when the tape F is pressed down by the stripper 28, each lifter pin 120 is placed in the lowered position, in which the lifter pin 120 is lowered by the tape F against the spring force of the lifter spring 124.

[0257] Each of the lifter pins 120 has a circumferential groove 126 in the outer periphery of the portion protruding from the upper surface 47 of the die plate 40. Each of the circumferential grooves 126 has a rectangular cross-sectional shape, similar to the guide groove 104 in the above-described embodiment. The left and right edge portions of the tape F enter the circumferential grooves 126, so that the tape F is raised (lifted) from the upper surface 47 of the die plate 40 in the raised position, and the tape F is placed on the upper surface 47 of the die plate 40 in the lowered position. Further, when the left and right edge portions of the tape F enter the circumferential grooves 126 in the left and right lifter pins 120, the lifter pins 120 restrict the movement of the tape F in the left and right directions and guide the intermittent conveyance of the tape F, and also restrict the downward movement of the tape F other than the upward movement of the tape F when performing the lifting.

[0258] As a result, when the tape F is conveyed in an intermittent manner or when the adhesive is applied to the adhesive application surface, the displacement of the tape F in the left and right directions and the upward and downward movements of the tape F is restricted. By this restriction, the flapping of the tape F is suppressed, and the adhesive is accurately applied to the adhesive application surface.

[0259] Except for the above-described lifting structure of the belt F by the lifter pin 120, this embodiment is substantially the same as the above-described embodiment, and thus the effects of the above-described embodiment are also obtained in this embodiment.

[0260] In this embodiment, the lifter pin 120 also serves as a guiding member for the belt F, and thus the number of components is reduced.

[0261] Other embodiments of the manufacturing apparatus for a laminated iron core according to the present invention are as follows.

[0262] (1) A manufacturing apparatus for a laminated iron core, wherein the laminated iron core is formed by laminating and bonding iron core thin plates, the iron core thin plates are formed by blanking a steel strip into a predetermined shape, and the manufacturing apparatus includes: an upper holder and a lower holder; a plurality of punches and dies, the plurality of punches and dies are respectively provided on the upper holder and the lower holder, and the plurality of punches and dies sequentially blank the iron core thin plates from the steel strip conveyed in an intermittent manner; a guide pin, the guide pin is provided on the upper holder, and the guide pin is configured to be inserted through a guide hole formed in the steel strip at each conveying position to perform positioning of the steel strip; and an adhesive coating device, the adhesive coating device is provided on at least one of the upper holder and the lower holder, and the adhesive coating device coats an adhesive coating surface at a portion of the steel strip corresponding to each iron core thin plate with an adhesive coating.

[0263] (2) A manufacturing apparatus for a laminated iron core, wherein the laminated iron core is formed by laminating and bonding iron core thin plates, the iron core thin plates are formed by blanking a steel strip into a predetermined shape, and the manufacturing apparatus includes: an upper holder and a lower holder; a plurality of punches and dies, the plurality of punches and dies are respectively provided on the upper holder and the lower holder, and the plurality of punches and dies sequentially blank the iron core thin plates from the steel strip conveyed in an intermittent manner; a stripper plate, the stripper plate is provided on the upper holder so as to be displaceable in a vertical direction, and the stripper plate has a lower surface opposed to an upper surface of the die; and an adhesive coating device, the adhesive coating device is provided on at least one of the upper holder and the lower holder, and the adhesive coating device coats an adhesive on an adhesive coating surface at a portion of the steel strip corresponding to each iron core thin plate. In this case, the manufacturing apparatus for the laminated iron core may further include a stripper spring that biases the stripper plate toward the lower holder, and the lower surface of the stripper plate may be configured to press the steel strip against the upper surface of the die by the spring force of the stripper spring. Further, the stripper plate may be configured to press the steel strip against the upper surface of the die by the lower surface until the punch is disengaged from the die.

[0264] (3) A manufacturing apparatus for a laminated iron core, wherein the laminated iron core is formed by laminating and bonding thin iron core plates, the thin iron core plates being formed by blanking a steel strip into a predetermined shape, the manufacturing apparatus comprising: an upper retainer and a lower retainer; a plurality of punches and dies, the plurality of punches and dies being respectively provided on the upper retainer and the lower retainer, the plurality of punches and dies sequentially blanking the thin iron core plates from the steel strip conveyed in an intermittent manner; a plurality of lifters, the plurality of lifters being provided on the lower retainer so as to be displaceable in the vertical direction, the plurality of lifters separating the steel strip from the upper surface of the die by abutting against the lower surface of the steel strip; and an adhesive coating device, the adhesive coating device being provided on at least one of the upper retainer and the lower retainer, the adhesive coating device coating an adhesive on an adhesive coating surface of the steel strip corresponding to each thin iron core plate. In this case, a plurality of lifter springs may be further included, and when the stripping plate ascends, the plurality of lifter springs apply an upward force to the lifters to separate the steel strip from the upper surface of the die in a case where the steel strip is vertically supported by the stripping plate and the lifters. <C

[0265] The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and as will be readily understood by those skilled in the art, appropriate modifications can be made without departing from the spirit of the present invention.

[0266] For example, the coating table 60 for the adhesive (first adhesive liquid) may repeatedly descend and ascend in synchronization with the pressing operation, rather than only descending when forming the thin iron core plate for separation. The hardening accelerator or initiator (second adhesive liquid) may be continuously coated or may be coated only when the tape F stops. Additionally, the hardening accelerator or initiator (second adhesive liquid) may be coated over the entire tape F or a part of the tape F. Further, a plurality of adhesive accumulation portions 62 may be provided such that the adhesive can be supplied from the adhesive accumulation portions 62 to the discharge holes 64 in the corresponding areas. The adhesive may be continuously supplied to the adhesive accumulation portions 62 or may be intermittently supplied to the adhesive accumulation portions 62 in synchronization with the pressing operation. Coating the adhesive is not limited to transfer, and spray-type emission coating may be used. Coating of the adhesive onto the tape F may be performed on the upper surface or both surfaces (that is, the lower surface and the upper surface) of the tape F. The coating shape of the adhesive is not limited to a dot shape, and may be an annular shape, a triangle, a square, a deformed shape, etc.

[0267] In some types of laminated iron cores, internal shape stamping is unnecessary. In this case, it is only necessary to omit the internal shape stamping. Additionally, the guide pins 84 are not essential. As the shape of the laminated iron core in the plan view, in addition to the annular shape and the circular shape, a square, a T shape, a U shape, etc. may be used.

[0268] The belt F does not necessarily need to be pressed against the upper surfaces of the die plate 40, the dies 44, 42, and 46, and the coating table 60 through the stripping plate 32, and the stripping plate 32 can be configured to restrict the vertical displacement of the belt F between the stripping plate 32 and the upper surfaces of the die plate 40, the dies 44 and 46, and the coating table 60 until the punches 22 and 24 are disengaged from the dies 44 and 46.

[0269] The arrangement of the stripping plate 32 and the lifter pins 110 can be such that, in addition to the arrangement where the stripping plate 32 and the lifter pins 110 are offset in the left - right direction and do not overlap each other in the plan view, the stripping plate 32 and the lifter pins 110 overlap each other in the plan view to sandwich the belt F therebetween vertically. The lifter pins 110 can be arranged in the middle portion of the belt F in the left - right direction.

[0270] Preferably, considering that the conveying distance of the belt F becomes shorter after the adhesive is applied, the application of the adhesive by the adhesive application device 50 is performed immediately before the outer diameter stamping step, but it is not necessary to perform the application of the adhesive by the adhesive application device 50 immediately before the outer diameter stamping step. The heating step and the rotating stacking step are not necessary.

[0271] In addition, not every component described in the above - mentioned embodiments is necessary, and the components to be adopted can be appropriately selected without departing from the gist of the present invention. For example, the guide pins, the guiding members, and the demolding structure are not necessary and can be omitted.

Claims

1. A manufacturing apparatus for a laminated iron core, the laminated iron core being formed by laminating and bonding iron core thin plates, the iron core thin plates being formed by blanking a steel strip into a predetermined shape, the manufacturing apparatus comprising: An upper retainer and a lower retainer; A die plate provided on the lower retainer; Left and right guiding members provided on the lower retainer, the left and right guiding members guiding the conveyance of the steel strip along the intermittent conveyance direction of the steel strip and restricting the upward movement of the steel strip; An adhesive application station including an adhesive application device provided on at least one of the upper retainer and the lower retainer, the adhesive application device applying an adhesive to an adhesive application surface at a portion of the steel strip corresponding to each iron core thin plate; A guide pin provided on the upper retainer, the guide pin being configured to be inserted through a guide hole formed in the steel strip in the adhesive application device to perform positioning of the steel strip; A stripping plate provided on the upper retainer so as to be displaceable in the vertical direction, the stripping plate having a lower surface opposed to the upper surface of the die plate; and An internal shape punching station and an external shape punching station for punching the iron core thin plates from the steel strip, wherein each of the left and right guiding members has a strip shape that is long in the intermittent conveyance direction of the steel strip, and is provided at intervals in the intermittent conveyance direction of the steel strip except for regions corresponding to the internal shape punching station, the external shape punching station, and the adhesive application station, wherein the manufacturing apparatus further comprises: A plurality of lifters provided on the lower retainer so as to be displaceable in the vertical direction, the plurality of lifters separating the steel strip from the upper surface of the die plate by abutting against the lower surface of the steel strip; and A plurality of lifter springs that, when the stripping plate rises, apply an upward force to each of the lifters in a case where the stripping plate abuts against the upper surface of the steel strip and each of the lifters abuts against the lower surface of the steel strip to separate the steel strip from the upper surface of the die plate, and wherein each of the lifters is formed by a lifter pin, the lifter pins being provided at a predetermined interval on both the left and right sides of the die plate in the intermittent conveyance direction of the steel strip, and in a plan view, the arrangement positions of the lifter pins overlap the arrangement positions of the guiding members.

2. The manufacturing apparatus for a laminated iron core according to claim 1, wherein, The internal shape punching station and the external shape punching station include a plurality of punches and a plurality of dies respectively provided on the upper retainer and the lower retainer, the plurality of punches and the plurality of dies sequentially blanking the iron core thin plates from the intermittently conveyed steel strip.

3. The manufacturing apparatus for a laminated iron core according to claim 1 or 2, the manufacturing apparatus further comprising a stripper spring that biases the stripper plate toward the lower retainer, wherein the stripper plate is configured to press the steel strip against the upper surface of the die plate by the spring force of the stripper spring.

4. The manufacturing apparatus of the laminated iron core according to claim 2, wherein, The stripper plate is configured to press the steel strip against the upper surface of the die plate until the punch disengages from the die.

5. The manufacturing apparatus for a laminated iron core according to claim 3, wherein: the guide pin includes a straight shaft portion; and the straight shaft portion is positioned to project downward from the lower surface of the stripper plate in a state where the stripper plate is in the lowest position relative to the upper retainer by the biasing force of the stripper spring.

6. The manufacturing apparatus for a laminated iron core according to claim 1 or 2, wherein, The adhesive coating device is a transfer type adhesive coating device including a plurality of discharge holes that discharge the adhesive toward the adhesive coating surface to transfer the adhesive to each of a plurality of predetermined positions on the adhesive coating surface.

7. The manufacturing apparatus for a laminated iron core according to claim 6, wherein, The adhesive coating device includes: an adhesive supply device that supplies the adhesive to each of the discharge holes at a predetermined pressure; and a forward - retract drive device that moves each of the discharge holes between a transfer position and a non - transfer position, in the transfer position, each of the discharge holes can transfer the adhesive to the adhesive coating surface, and in the non - transfer position, each of the discharge holes retracts from the transfer position and cannot transfer the adhesive.

Images