Manufacturing device and manufacturing method of laminated iron core

Abstract

To accurately apply an adhesive to an adhesive-applied surface.SOLUTION: A guide member 100 is provided to guide the transfer of a strip-shaped thin steel plate F along an intermittent transfer direction of the strip-shaped thin steel plate F and restrict the upward movement of the strip-shaped thin steel plate F, and an adhesive coating device 50 that applies the adhesive to the adhesive-applied surface of a portion corresponding to an iron core thin plate A (W) is provided.SELECTED DRAWING: Figure 8B

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for manufacturing a laminated core, and more particularly to an apparatus and method for manufacturing a bonded laminated core in which a plurality of laminated thin core plates are bonded together with an adhesive. [Background technology]

[0002] A known laminated core used in the stators and rotors of rotating electrical machines is a bonded laminated core, which is formed by stacking thin core plates punched out of an intermittently transported strip-shaped thin steel sheet using a progressive die including a plurality of punching dies (die set) made of a punch and a die in sequence within the die and bonding them together with an adhesive such as an epoxy resin-based adhesive (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japan Patent Office Publication No. 2001-321850 [Patent Document 2] Japan Patent Office Publication No. 2009-124828 Summary of the Invention [Problem to be solved by the invention]

[0004] The application of adhesive to the adhesive-coated surface of the iron core thin plate (belt-shaped thin steel plate) must be performed accurately at a predetermined position on the adhesive-coated surface so that the designed adhesive strength is obtained and the adhesive does not drip to the outside, etc. It is also required that the adhesive on the adhesive-coated surface does not spread or scatter around due to vibration of the iron core thin plate (belt-shaped thin steel plate) when it is moved.

[0005] The problem to be solved by the present invention is to ensure that adhesive is accurately applied to an adhesive application surface. [Means for solving the problem]

[0006] The laminated core manufacturing apparatus according to the present invention is an apparatus for manufacturing laminated iron cores by stacking and bonding iron core sheets punched into a predetermined shape from a strip of thin steel sheet, and comprises an upper holder and a lower holder, a plurality of punches and dies provided on the upper holder and the lower holder, respectively, for successively punching out iron core sheets from the intermittently transported strip of thin steel sheet, a guide member provided on the lower holder for guiding the transport of the strip of thin steel sheet along the intermittent transport direction of the strip of thin steel sheet and limiting the upward movement of the strip of thin steel sheet, and an adhesive application device provided on at least one of the upper holder and the lower holder for applying adhesive to the adhesive application surface of the strip of thin steel sheet in the portion corresponding to the iron core sheet.

[0007] According to this configuration, the adhesive is applied to the adhesive application surface while the upward movement of the strip-shaped thin steel plate is restricted by the guide member, so that the adhesive can be applied accurately to the adhesive application surface.

[0008] The guide member has a structure that limits the upward movement of the strip-shaped thin steel plate by abutting against it, and also has a structure that limits the left-right movement of the strip-shaped thin steel plate by abutting against it, thereby guiding the intermittent transport of the strip-shaped thin steel plate.

[0009] In this case, the adhesive is applied to the adhesive application surface while the strip-shaped thin steel plate is restricted in both upward and left-right movement, so that the adhesive can be applied to the adhesive application surface more accurately.

[0010] The laminated iron core manufacturing apparatus according to the present invention preferably further has a pilot pin provided on the upper holder and inserted into a pilot hole formed in the strip of steel plate to position the strip of steel plate at each transfer position.

[0011] According to this configuration, adhesive is applied to the adhesive application surface while the pilot pin is inserted into the pilot hole formed in the strip-shaped thin steel plate, so that adhesive can be accurately applied to the adhesive application surface.

[0012] The laminated core manufacturing apparatus according to the present invention preferably further comprises a stripper plate disposed on the upper holder so as to be vertically displaceable, and having a lower surface facing the upper surface of the die.

[0013] According to this configuration, the stripper plate can restrict the vertical movement of the strip-shaped thin steel plate, so that the adhesive can be accurately applied to the adhesive application surface.

[0014] The manufacturing apparatus for laminated iron cores according to the present invention preferably further has a stripper spring that urges the stripper plate toward the lower holder, and the stripper plate is configured to press the strip-shaped thin steel plate against the upper surface of the die by the spring force of the stripper spring.

[0015] According to this configuration, adhesive can be applied to the adhesive application surface when or in the state in which the strip-shaped thin steel plate is pressed against the die by the stripper plate, and adhesive can be applied accurately to the adhesive application surface.

[0016] The manufacturing apparatus for laminated iron cores according to the present invention is preferably configured so that the stripper plate presses the strip of thin steel sheet against the upper surface of the die until the punch leaves the die, more preferably until the punch leaves the strip of thin steel sheet.

[0017] According to this configuration, during the process of rising of the upper holder after punching, the strip of steel sheet is maintained pressed against the upper surface of the die by the stripper plate until the punch has come out of the die or until the punch has come out of the strip of steel sheet, thereby preventing the strip of steel sheet from shaking during the process of rising of the upper holder and preventing the adhesive applied to the strip of steel sheet from scattering.

[0018] In the laminated iron core manufacturing apparatus according to the present invention, preferably, the pilot pin includes a straight shaft portion, and the straight shaft portion is in a position protruding downward from the underside of the stripper plate when the stripper plate is in its lowest position relative to the upper holder due to the force of the stripper spring.

[0019] According to this configuration, when the upper holder is descending, the straight shaft portion of the pilot pin enters the pilot hole before the lower surface of the stripper plate abuts against the strip-shaped thin steel plate, so that the positioning of the strip-shaped thin steel plate can be performed smoothly without being hindered by the constraint of the strip-shaped thin steel plate by the stripper plate.

[0020] The laminated iron core manufacturing apparatus according to the present invention preferably further has a plurality of lifters which are mounted on the lower holder so as to be displaceable in the vertical direction and which abut against the lower surface of the strip-shaped thin steel plate to separate the strip-shaped thin steel plate from the upper surface of the die.

[0021] With this configuration, the strip-shaped thin steel plate can be lifted up from the upper surface of the die during intermittent transfer of the strip-shaped thin steel plate, and even if the adhesive-coated surface is the underside of the strip-shaped thin steel plate, the adhesive applied to the adhesive-coated surface is not rubbed by the upper surface of the die.

[0022] The manufacturing apparatus for laminated iron cores according to the present invention preferably further includes a plurality of lifters which are vertically displaceable on the lower holder and which abut against the underside of the strip-shaped thin steel plate to separate the strip-shaped thin steel plate from the upper surface of the die, and a plurality of lifter springs which urge each of the lifters upwardly when the stripper plate is raised so that the stripper plate abuts against the upper surface of the strip-shaped thin steel plate and each of the lifters abuts against the underside of the strip-shaped thin steel plate to separate the strip-shaped thin steel plate from the upper surface of the die.

[0023] According to this configuration, after the adhesive is applied, the iron core thin plate is returned to the lifted-up state (separated state) while being supported from above and below by the lifter and the stripper plate, thereby preventing the strip-shaped thin steel plate from shaking during the lift-up process and preventing the adhesive applied to the strip-shaped thin steel plate from scattering.

[0024] In the laminated core manufacturing apparatus according to the present invention, preferably, each of the lifters also serves as the guide member.

[0025] According to this configuration, the number of parts can be reduced.

[0026] When the lifter also serves as a guide member, the lifter may be configured with a lifter pin having a circumferential groove on the upper outer periphery, and the left and right side edges of the strip steel sheet may fit into the circumferential groove. In this case, when the strip steel sheet is lifted up by the lifter, the upward and downward movements of the strip steel sheet are restricted according to the vertical width of the circumferential groove, and flapping of the strip steel sheet during intermittent transfer is suppressed.

[0027] In the laminated iron core manufacturing apparatus according to the present invention, preferably, the adhesive application device is of a transfer type that includes a plurality of discharge holes that discharge adhesive toward the adhesive application surface in order to transfer the adhesive to each of a plurality of predetermined positions on the adhesive application surface.

[0028] According to this configuration, the adhesive can be accurately applied to the adhesive application surface by transfer.

[0029] In the laminated iron core manufacturing apparatus according to the present invention, the adhesive application device preferably has an adhesive supply device which supplies the adhesive to each of the discharge holes at a predetermined pressure, and an advance / retract drive device which moves each of the discharge holes between a transfer position where the adhesive can be transferred to the adhesive application surface and a non-transfer position where the adhesive cannot be transferred by retreating from the transfer position.

[0030] According to this configuration, simply by selectively setting the position of the discharge hole to either the transfer position or the non-transfer position, the transfer or non-transfer of adhesive to the adhesive application surface can be selectively set.

[0031] The laminated core manufacturing apparatus according to the present invention is an apparatus for manufacturing a laminated core by stacking and bonding core sheets which are punched out into a predetermined shape from a strip-shaped thin steel sheet, and includes an upper holder and a lower holder, a plurality of punches and dies provided on the upper holder and the lower holder for successively punching out core sheets from the intermittently transferred strip-shaped thin steel sheet, pilot pins provided on the upper holder for being inserted into pilot holes formed in the strip-shaped thin steel sheet to position the strip-shaped thin steel sheet at each transfer position, a stripper plate provided on the upper holder so as to be displaceable in the vertical direction and having a lower surface facing an upper surface of the die, and a movable member for moving the stripper plate. The apparatus includes a stripper spring that urges the strip toward the lower holder, a plurality of lifters that are vertically displaceable on the lower holder and abut the underside of the strip of steel plate, a plurality of lifter springs that urge each of the lifters upwardly so as to lift the strip of steel plate above the upper surface of the die when the stripper plate is raised and the strip of steel plate abuts the upper surface of the strip of steel plate and each of the lifters abuts the underside of the strip of steel plate, and an adhesive application device that is provided on at least one of the upper holder and the lower holder and applies adhesive to the adhesive application surface of the portion of the strip of steel plate that corresponds to the iron core plate.

[0032] According to this configuration, the pilot pins are inserted into the pilot holes of the strip steel sheet, and the adhesive can be applied to the adhesive application surface when or while the strip steel sheet is pressed against the upper surface of the die by the stripper plate, so that the adhesive can be applied accurately to the adhesive application surface. Moreover, after the adhesive is applied, the strip steel sheet is returned to the lifted-up state while being supported from above and below by the lifter and the stripper plate, so that the strip steel sheet is prevented from shaking during the floating process, and the adhesive applied to the strip steel sheet is prevented from scattering.

[0033] The manufacturing method of a laminated core according to the present invention is a manufacturing method of a laminated core in which iron core sheets are punched out of a strip of thin steel sheet into a predetermined shape using a press device having an upper holder and a lower holder, and includes a transfer process in which the strip of thin steel sheet is intermittently transferred while a guide member provided on the lower holder restricts the upward movement of the strip of thin steel sheet and guides the transfer along the intermittent transfer direction of the strip of thin steel sheet, a punching process in which the upper holder is lowered to punch out the outer shape of the core sheet using a punch and die provided on the upper and lower holders, and an application process in which adhesive is applied to the adhesive application surface of the strip of thin steel sheet by an adhesive application device provided on at least one of the upper and lower holders before the punching process.

[0034] According to this manufacturing method, the intermittent transport of the strip-shaped thin steel plate is guided by a guide member, and the adhesive is applied to the adhesive-coated surface while the guide member restricts the upward movement of the strip-shaped thin steel plate, so that the adhesive can be applied accurately to the adhesive-coated surface.

[0035] In the manufacturing method of a laminated iron core according to the present invention, preferably, the transfer process, when the upper holder is in a raised state, involves intermittently transferring the strip-shaped thin steel plate in a lifted-up state away from the upper surface of a die provided on the lower holder by a lifter that is movable up and down on the lower holder and is biased upward by a lifter spring.

[0036] According to this manufacturing method, even if the adhesive-coated surface is the lower surface of the strip-shaped thin steel plate, the adhesive applied to the adhesive-coated surface is not rubbed by the upper surface of the die.

[0037] The manufacturing method of a laminated iron core according to the present invention preferably further includes a pilot insertion process of inserting a pilot pin provided on the upper holder into a pilot hole formed in the strip-shaped thin steel plate during the descent of the upper holder after completion of the transfer process.

[0038] According to this manufacturing method, the steel strip is positioned accurately, so that the adhesive can be applied accurately to the adhesive application surface.

[0039] The manufacturing method of a laminated core according to the present invention preferably further includes a pressing process in which a stripper plate suspended from the upper holder by a stripper spring is pressed against the upper surface of a die provided on the lower holder while the upper holder is descending after completion of the pilot insertion process, accompanied by the downward movement of the lifter, to press the strip-shaped thin steel plate against the upper surface of a die provided on the lower holder.

[0040] According to this manufacturing method, after the pilot insertion process is completed, the strip steel sheet is pressed against the upper surface of the die. In other words, the pilot pin is inserted into the pilot hole of the strip steel sheet before the strip steel sheet is pressed against the upper surface of the die and restrained, so that the pilot pin can be inserted smoothly into the pilot hole.

[0041] In the manufacturing method of a laminated core according to the present invention, preferably, the application process involves applying adhesive when the pilot pin is inserted into the pilot hole and the strip steel plate is pressed against the upper surface of the die by the stripper plate as the lifter moves downward, or in a state in which the strip steel plate is pressed against the upper surface of the die, and when the upper holder rises after adhesive application is completed, the lifter moves upward and abuts against the lower surface of the strip steel plate and the stripper plate abuts against the upper surface of the strip steel plate, returning the strip steel plate to the lifted-up state.

[0042] According to this manufacturing method, the adhesive is applied to the adhesive application surface when or while the stripper plate is pressing the strip of steel sheet against the die, so that the adhesive can be applied accurately to the adhesive application surface. Moreover, the strip of steel sheet is prevented from shaking during the upward movement of the upper holder, and the adhesive applied to the strip of steel sheet is prevented from scattering.

[0043] The method for manufacturing a laminated core according to the present invention is a method for manufacturing a laminated core by laminating and bonding thin iron core plates that have been punched into a predetermined shape from a strip-shaped thin steel sheet using a press device having an upper holder and a lower holder, and includes a transfer process in which, when the upper holder is in a raised state, the strip-shaped thin steel sheet is intermittently transferred in a lifted-up state away from an upper surface of a die provided on the lower holder by a lifter that is provided on the lower holder so as to be movable up and down and is biased upward by a lifter spring. a pilot insertion step of inserting pilot pins provided on the upper holder into pilot holes formed in the strip-shaped thin steel plate during the descent of the upper holder after the completion of the transfer step; a pressing step of pressing a stripper plate suspended by a stripper spring on the upper holder against an upper surface of a die provided on the lower holder with the descent movement of the lifter during the descent of the upper holder after the completion of the pilot insertion step, against an upper surface of a die provided on the lower holder, with the lifter moving downward; At each of the pressing positions, a punching step is performed in which an inner shape and an outer shape are sequentially punched out of the strip-shaped thin steel plate by a plurality of die sets of punches and dies provided on the upper and lower holders by further lowering the upper holder after the completion of the pressing step, and a coating step is performed in which an adhesive is applied to an adhesive application surface of the strip-shaped thin steel plate by an adhesive application device provided on at least one of the upper and lower holders and set in line with the press position between the press position for punching out the inner shape and the press position for punching out the outer shape. and a step of applying adhesive to the strip-shaped thin steel plate when the pilot pin is inserted into the pilot hole and the strip-shaped thin steel plate is pressed against the upper surface of the die by the stripper plate with the lifter moving downward, or while the strip-shaped thin steel plate is being pressed against the upper surface of the die. After the adhesive application is completed, the upper holder rises, and the lifter moves upward to abut against the lower surface of the strip-shaped thin steel plate and the stripper plate abuts against the upper surface of the strip-shaped thin steel plate, returning the strip-shaped thin steel plate to the lifted-up state.

[0044] According to this manufacturing method, the pilot pins are inserted into the pilot holes of the strip steel sheet, and the adhesive is applied to the adhesive application surface when or while the strip steel sheet is pressed against the upper surface of the die by the stripper plate, so that the adhesive can be applied accurately to the adhesive application surface. Moreover, after the adhesive is applied, the strip steel sheet is returned to the lifted-up state while being supported from above and below by the lifter and the stripper plate, so that the strip steel sheet is prevented from shaking during the lift-up process, and the adhesive applied to the strip steel sheet is prevented from scattering.

[0045] In the manufacturing method of a laminated iron core according to the present invention, the application step preferably includes a step of ejecting adhesive from each of a plurality of ejection holes toward the adhesive application surface and transferring the adhesive to each of a plurality of predetermined positions on the adhesive application surface.

[0046] According to this manufacturing method, the application of adhesive to the adhesive application surface is performed finely and accurately by transfer.

[0047] In the method for manufacturing a laminated core according to the present invention, the core thin plate includes a plurality of teeth, and each of the teeth has at least one of the application points.

[0048] According to this manufacturing method, adjacent core thin plates are also bonded to each other at the teeth portions, producing a laminated core with high adhesive strength. Effect of the Invention

[0049] According to the laminated core manufacturing apparatus and manufacturing method of the present invention, the adhesive can be applied accurately to the adhesive application surface. [Brief description of the drawings]

[0050] [Figure 1] FIG. 1 is a plan view showing an example of an iron core thin plate used in a stator of a stepping motor; [Diagram 2] FIG. 2 is an explanatory diagram showing a strip layout in a progressive die device used to manufacture the iron core thin plate shown in FIG. [Diagram 3] FIG. 1 is a plan view showing a schematic of a laminated core thin plate manufactured by the laminated core manufacturing apparatus and manufacturing method according to the present invention; [Figure 4] FIG. 4 is an explanatory diagram showing one embodiment of a strip layout in a progressive die device used in manufacturing the laminated core shown in FIG. [Diagram 5] FIG. 1 is a schematic diagram showing one embodiment of a laminated core manufacturing apparatus according to the present invention. [Figure 6] FIG. 1 is a cross-sectional view showing an adhesive device used in the laminated core manufacturing apparatus according to the present embodiment. [Figure 7] FIG. 1 is an enlarged cross-sectional view of a main part of an adhesive device according to an embodiment of the present invention; [Figure 8A] 1 is a cross-sectional view of an inner shape punching station of the manufacturing apparatus according to the present embodiment in a top dead center state. [Figure 8B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to an embodiment of the present invention in a top dead center state. [Figure 9A] FIG. 1 is a cross-sectional view of the inner shape punching station of the manufacturing apparatus according to the present embodiment during a descending process 1. [Figure 9B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to the present embodiment during a descending process 1. [Figure 10A] FIG. 2 is a cross-sectional view of the inner shape punching station of the manufacturing apparatus according to the present embodiment during the lowering process 2. [Figure 10B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to the present embodiment during a descending process 2. [Figure 11A] FIG. 3 is a cross-sectional view of the inner shape punching station of the manufacturing apparatus according to the present embodiment during the lowering process 3. [Figure 11B] 3 is a cross-sectional view of the adhesive application station of the manufacturing apparatus according to the present embodiment during a descending process 3. [Figure 12A] 1 is a cross-sectional view of the inner shape punching station of the manufacturing apparatus according to the present embodiment at the bottom dead center. [Figure 12B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to an embodiment of the present invention in a bottom dead center state. [Figure 13A] FIG. 1 is a cross-sectional view of an inner shape punching station of the manufacturing apparatus according to the present embodiment during a rising process 1. [Figure 13B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to the present embodiment during a rising process 1. [Figure 14A] FIG. 2 is a cross-sectional view of the inner shape punching station of the manufacturing apparatus according to the present embodiment during the ascending process 2. [Figure 14B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to the present embodiment during a rising process 2. [Figure 15A] FIG. 3 is a cross-sectional view of the inner shape punching station of the manufacturing apparatus according to the present embodiment during the ascending process 3. [Figure 15B] 3 is a cross-sectional view of the adhesive application station of the manufacturing apparatus according to the present embodiment during the ascending process 3. [Figure 16] FIG. 1 is an enlarged cross-sectional view of a lift-up portion of the manufacturing apparatus according to the present embodiment in a top dead center state. [Figure 17] FIG. 1 is an enlarged cross-sectional view of a lift-up portion of the manufacturing apparatus according to the present embodiment during a descending process 2. [Figure 18] FIG. 1 is an enlarged cross-sectional view of a lift-up portion of the manufacturing apparatus according to the present embodiment when the lift-up portion is in a bottom dead center state. [Figure 19] FIG. 1 is an enlarged cross-sectional view of a lift-up portion of the manufacturing apparatus according to the present embodiment during a lifting process 1. [Figure 20] FIG. 4 is an explanatory diagram showing another embodiment of a strip layout in a progressive die device used in manufacturing the laminated core shown in FIG. [Figure 21] FIG. 4 is an explanatory diagram showing another embodiment of a strip layout in a progressive die device used in manufacturing the laminated core shown in FIG. [Figure 22A] 13 is a cross-sectional view of an inner shape punching station of a manufacturing apparatus according to another embodiment in a top dead center state; [Figure 22B] 1 is a cross-sectional view of an adhesive application station of a manufacturing apparatus according to another embodiment in a top dead center state; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings.

[0052] First, as a specific example of a laminated core, a laminated core used in the stator of a stepping motor will be described with reference to FIG.

[0053] The laminated core is made by stacking multiple identically shaped thin core plates A. The thin core plate A is made by punching out a strip of thin steel plate, i.e., a hoop material F, into a specified shape by press working using a progressive die, and has an annular yoke portion B formed by punching out the outer shape, multiple teeth portions (magnetic pole portions) C formed by punching out the inner shape protruding radially inward from the yoke portion B, and multiple through holes D punched out in the yoke portion B, with adjacent ones being bonded together by adhesive applied in a circular dot pattern at multiple application points E1, E2 on one surface (adhesive application surface) of the yoke portion B and the teeth portion C.

[0054] The adhesives used here include anaerobic adhesives (adhesive + curing accelerator), one-component epoxy resin adhesives, two-component epoxy resin adhesives (first adhesive component + second adhesive component or main component + initiator), thermosetting adhesives such as acrylic resin adhesives, and moisture-curing adhesives.

[0055] In addition, in Figure 1, for the sake of convenience, each application point E1, E2 is shown on the upper surface of the iron core thin plate A, but in reality, each application point E1, E2 is set on the lower surface of the iron core thin plate A so that the adhesive is applied to the lower surface (adhesive application surface) of the iron core thin plate A.

[0056] The manufacturing process of the laminated iron core includes, in order, first half punching steps 1 to 5, adhesive application step 6, outer shape punching step 7, rotary lamination step 8, and heating step 9, as shown in Figure 2, with the hoop material F being intermittently transferred in a progressive die device (laminated iron core manufacturing device).

[0057] In the first half of the punching process, punching 1 of a pilot hole P in the hoop material F, punching 2 of an inner pilot hole d1 and a through hole D, punching 3 of a slot portion S1, punching 4 of an inner shape d2, and punching 5 of a slit S2 between the teeth and a groove-shaped portion m at the tooth tip are carried out in sequence using each die set (not shown) consisting of a punch and die of a shape corresponding to each punching process, and the basic shape excluding the outer shape of the core thin plate A is formed.

[0058] The adhesive application step 6 is performed after the first half punching steps 1 to 5. The adhesive is applied to the hoop material F in a circular dot shape at a plurality of application points E1 set at positions corresponding to the slots S1 of the yoke portion B and at two application points E2 set at each of the teeth portions C, as shown in detail in FIG. 1. A known anaerobic adhesive is used as the adhesive. Also, in FIG. 2, for the sake of convenience, the application points E1 and E2 are shown on the upper surface side of the iron core thin plate A, but in reality, the application points E1 and E2 are set on the lower surface side of the iron core thin plate A.

[0059] The outer shape punching process 7 is carried out after completion of the adhesive application process 6. The outer shape punching process 7 is carried out by a die set (not shown) consisting of a punch and a die having a shape corresponding to the outer shape d3 of the iron core thin plate A.

[0060] The rotary lamination process 8 is carried out following the outer shape punching process 7. The die in the outer shape punching process 7 is a rotary die, which rotates a predetermined angle, for example, 90 degrees, around its own central axis each time the outer shape of one core sheet A is punched. As a result, the core sheets A punched out in the outer shape punching process 7 are sequentially stacked on the group of core sheets G that have already been punched and stacked in the rotary die, while changing their position around the central axis. This rotary stacking eliminates the effects of minute sheet thickness deviations that may occur in each core sheet A, making it possible to accurately manage the stack thickness of the product (laminated core). The group of core sheets G is then sequentially pressed into a squeeze ring (not shown) that is connected below the rotary die.

[0061] When the newly punched core thin plate A is stacked on top of the iron core thin plate group G, the underside of the newly punched core thin plate A is brought into close contact with the upper surface of the iron core thin plate A located in the top layer of the iron core thin plate group G, so that the adhesive applied in a circular dot pattern to each of the application points E1, E2 on the underside of the newly punched core thin plate A mixes with the hardening accelerator that has been applied in advance to the upper surface of the iron core thin plate A located in the top layer.

[0062] The heating step 9 is carried out after the rotation and stacking step 8 is completed. A heating device (not shown) is provided below the squeeze ring, and this heating device heats the iron core thin plate group G as it moves downward. This heats and hardens the adhesive between each of the iron core thin plates A, increasing the adhesive strength. An example of such an adhesive heating device is a heater device that blows hot air onto the iron core thin plate group G. After heating by the heating device, the iron core thin plate group G is separated at the position of each measuring iron core thin plate A, and a laminated iron core M consisting of a predetermined number of iron core thin plates A is completed.

[0063] Next, one embodiment of a laminated core manufacturing apparatus 10 will be described with reference to Figures 4 and 5. In the following explanation, for simplicity, an iron core sheet W will be described which is typified as an annular shape as shown in Figure 3. The iron core sheet W is formed by punching out a circular inner shape IS and a circular outer shape OS, and adhesive is applied in dot form to application points E set at multiple locations in the circumferential direction on the underside (adhesive application surface) of the annular portion R obtained by these punching operations.

[0064] The manufacturing apparatus 10 is of a progressive die type, and as shown in Figures 4 and 5, has a pilot hole punching station I, an inner shape punching station II, an idle station III, an adhesive application station IV, an idle station V, an outer shape punching station VI, and an idle station VII, which are arranged in the progressive direction, and each station I, II, IV, and VI, other than idle stations III, V, and VII, executes each process under the intermittent transfer of the hoop material F in the progressive direction. The punching processing performed at each of the pilot hole punching station I, inner shape punching station II, and outer shape punching station VI is indicated by diagonal lines. At idle stations III, V, and VII, the hoop material F is fed empty.

[0065] The manufacturing apparatus 10 has a plate-shaped upper holder 12 fixed to the underside of an upper ram (not shown) of a press machine, and a plate-shaped lower holder 14 fixed directly opposite the upper holder 12 to the top surface of a lower table (not shown) of the same press machine.

[0066] A pilot hole punch 20, an inner shape punch 22, and an outer shape punch 24 are attached to the lower part of the upper holder 12 by a backing plate 16 and a punch plate 18 at positions corresponding to each of stations I, II, and VI.

[0067] A stripper 28 is attached below the upper holder 12 by a hanging bolt (not shown) so as to be displaceable in the vertical direction. The stripper 28 is suspended by the hanging bolt (not shown) and has its lowest position set relative to the upper holder 12. The stripper 28 is formed by joining a plate-shaped stripper body 30 and a stripper plate 32, and a lower surface 33 of the stripper plate 32 faces an upper surface 47 of a die plate 40 and each of the dies 42, 44, 46, which will be described later. In other words, the stripper plate 32 has a lower surface 33 that faces an upper surface 47 of the die plate 40 and each of the dies 42, 44, 46. The stripper plate 32 has punch insertion holes 34, 36, 38 through which the punches 20, 22, 24 pass.

[0068] A plate-shaped die plate 40 is attached to the upper surface of the lower holder 14. A pilot hole punching die 42, an inner shape punching die 44, and an outer shape punching die 46 are attached to the die plate 40 at positions corresponding to each of the punching stations I, II, and VI. The pilot hole punching punch 20 and the pilot hole punching die 42, the inner shape punching punch 22 and the inner shape punching die 44, and the outer shape punching punch 24 and the outer shape punching die 46 correspond to each other and each form a die set.

[0069] Since the upper surfaces of the die plate 40 and the dies 42, 44, and 46 are flush with each other, these upper surfaces will hereinafter be collectively referred to as an upper surface 47 of the die plate 40.

[0070] An adhesive applicator 50 is provided at a position where the die plate 40 corresponds to the adhesive application station IV. The adhesive applicator 50 moves up and down by a cam mechanism 52 driven by a drive unit 54, and when in the raised position, applies (transfers) adhesive in dots to multiple locations (application points E) on the underside of the hoop material F for each press operation except for when measuring the number of laminated iron core thin plates W.

[0071] In pilot hole punching station I, a pilot hole P (see FIG. 4) is punched in the hoop material F with each press operation, in other words, with each intermittent transfer of the hoop material F, by a pilot hole punch 20 and a pilot hole punching die 42. The pilot holes P are provided near the edges on both sides (left and right sides) of the hoop material F in the intermittent transfer direction (forward feed direction).

[0072] In the inner shape punching station II, the inner shape IS (see FIG. 4) is punched out of the hoop material F by the inner shape punching punch 22 and the inner shape punching die 44 for each intermittent transfer of the hoop material F.

[0073] In adhesive application station IV, adhesive applicator 50, which is in the raised position, applies adhesive in the form of round dots to application points E on the underside of hoop material F. When measuring the number of laminated iron core thin plates W produced for each predetermined number of intermittent transfers, adhesive applicator 50 descends to the lowered position, and application of adhesive to hoop material F is suspended.

[0074] In the outer shape punching station VI, the outer shape OS (see FIG. 4) is punched out of the hoop material F by the outer shape punching punch 24 and the outer shape punching die 46. This punching completes the iron core thin sheets W, which then descend and are stacked one after the other in the outer shape punching die 46. The iron core thin sheets W stacked in the outer shape punching die 46 are bonded to each other with adhesive at application points E when they overlap one another, except for those for measurement that do not have adhesive applied.

[0075] At the outer shape punching station VI, the laminate of the iron core thin plates W is taken out downward and outward through a discharge hole 48 formed in the lower holder 14, and is transported to a post-processing step for heat-curing the adhesive, if necessary.

[0076] Next, the adhesive application device 50 will be described in detail with reference to FIGS.

[0077] The adhesive application device 50 is of a transfer type, and has an application table 60 formed by connecting an upper block 58 and a lower block 59. The application table 60 is inserted into holding holes 56 formed in the lower holder 14 and the die plate 40 so as to be movable up and down.

[0078] 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 movable cam 76 formed by a plate cam movably provided on the bottom of the lower block 59. The movable cam 76 is connected to the drive device 54, and is driven to reciprocate in the left-right direction as viewed in Fig. 6 by the drive device 54. The fixed cam 74 includes a sawtooth-shaped portion having sawtooth crests 74A and sawtooth valleys 74B alternately on the lower surface in the left-right direction, and the movable cam 76 includes a sawtooth-shaped portion having sawtooth crests 76A and sawtooth valleys 76B alternately on the upper surface.

[0079] As shown in the figure, when the movable cam 76 is in a position where the sawtooth portion 74A of the fixed cam 74 and the sawtooth portion 76A of the movable cam 76 are aligned, the coating table 60 is in the raised position (transfer position). In the raised position, the upper surface 61 of the upper block 58 is located lower than the upper surface 47 of the die plate 40 by the step α.

[0080] 6 by the driving device 54, and when the movable cam 76 is positioned at a position where the sawtooth valley portion 74B of the fixed cam 74 and the sawtooth crest portion 76A of the movable 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 positioned at the descended position. In this descended position (non-transfer position), the upper surface 61 of the upper block 58 is positioned below the upper surface 47 of the die plate 40 with a large step that exceeds the step α.

[0081] The upper block 58 is formed with an adhesive reservoir 62 formed by a circular groove, and a plurality of discharge holes 64 extending in the up-down direction (vertical direction) from the adhesive reservoir 62 to the horizontal upper surface 61 of the upper block 58 and opening on the upper surface 61. Each discharge hole 64 is disposed at a position corresponding to each application point E of the hoop material F (iron core thin plate W) located at the adhesive application station IV.

[0082] An internal block 66 is attached within the upper block 58. An adhesive supply passage 68 is formed in the internal block 66, which supplies adhesive to the adhesive reservoir 62. A flexible adhesive supply tube 70 is connected to the adhesive supply passage 68. The adhesive supply tube 70 is connected to an adhesive supply device 72. The adhesive supply device 72 pressurizes the adhesive to a predetermined pressure, measures the pressurized adhesive, and supplies it to the adhesive reservoir 62 at a predetermined flow rate via the adhesive supply tube 70 and the adhesive supply passage 68. As a result, adhesive is constantly supplied to each discharge hole 64 from the adhesive reservoir 62 at a predetermined pressure.

[0083] In this embodiment, two adhesive supply tubes 70 and two adhesive supply passages 68 are provided to supply adhesive to two locations 180 degrees apart in the circumferential direction of the adhesive reservoir 62, but this is not essential, and the number of these and the supply positions may be any number and supply positions necessary to ensure a supply amount of adhesive necessary to maintain an appropriate adhesive pressure throughout the entire adhesive reservoir 62. The appropriate adhesive pressure is determined by the size and number of discharge holes 64, the arrangement of discharge holes 64, etc.

[0084] The adhesive in the adhesive reservoir 62 is discharged above the application table 60 from each discharge hole 64. Since the pressure of the adhesive in the adhesive reservoir 62 is maintained at a predetermined value and the adhesive has a predetermined viscosity, the adhesive discharged to the outside from each discharge hole 64 always forms a mound N that is raised in a substantially hemispherical shape above the upper surface 61 of the upper block 58, as shown in Fig. 7. Since the height of the mound N is slightly greater than the step α, when the application table 60 is in the raised position (transfer position) and the hoop material F descends to a position where the lower surface of the hoop material F contacts the upper surface 47 of the die plate 40, the mound N of the adhesive at each discharge hole 64 contacts the lower surface of the hoop material F, and the adhesive is transferred to each application point E in the form of a round dot.

[0085] When the adhesive application device 50 forms the mounded portion N intermittently, the timing is set so that the mounded portion N is formed when the hoop material F is positioned at a position where the underside of the hoop material F contacts the upper surface 47 of the die plate 40, and the adhesive is transferred in the form of round dots to each application point E with the underside of the hoop material F contacting the upper surface 47 of the die plate 40.

[0086] The amount of adhesive transferred to each application point E can be controlled by the step α and the size (volume) of the mound N. The size of the mound N is quantitatively determined by the pressure of the adhesive in the adhesive reservoir 62, the viscosity of the adhesive, the inner diameter of the discharge hole 64, etc., so the amount of adhesive transferred to each application point E can be set to an optimal value by optimally setting these parameters.

[0087] In the transfer-type adhesive application using such discharge holes 64, the pitch between adjacent discharge holes 64 can be made small, so that the minimum pitch of application points E can be set to a dimension slightly larger than the inner diameter of the discharge holes 64. This makes it possible to set application points E at multiple locations on the teeth C, even if the teeth C are small. This contributes to improving the adhesive strength of the teeth C when multiple core thin plates W are laminated and bonded.

[0088] When the application table 60 is in the lowered position (non-transfer position), the upper surface 61 of the upper block 58 is positioned below the upper surface 47 of the die plate 40 with a large step that exceeds the step α, so that the adhesive mound portion N of a specified size does not come into contact with the underside of the hoop material F, and the adhesive is not transferred to the underside of the hoop material F. Therefore, when measuring to set the number of laminated iron core thin plates W, the application table 60 only needs to be moved to the lowered position.

[0089] As shown in Figures 8A and 8B, a knockout 26 is attached to the upper holder 12. Figure 8A shows an inner shape punching station II as a representative of the punching stations, and Figure 8B shows an adhesive application station IV.

[0090] The knockout 26 has a lower end 26A that abuts against the upper part of the stripper body 30, a shaft portion 26C that is fitted into a through hole 13 formed in the upper holder 12 so as to be vertically movable, and an upper end flange 26B that is located within a spring chamber 15 formed in the upper holder 12. The upper part of the spring chamber 15 is closed by a plug 17 fixed to the upper holder 12. A stripper spring (knockout spring) 29 made of a compression coil spring is provided between the plug 17 and the upper end flange 26B. The stripper spring 29 urges the knockout 26 downward.

[0091] The lowest position (bottom dead center position) of the upper holder 12 is determined by the lower surface of the upper holder 12 abutting against the upper surfaces of stoppers 82 provided on both the left and right sides of the lower holder 14 at the bottom dead center of an upper ram (not shown) of the press machine, as shown in Figures 12A and 12B. When the upper holder 12 is located at the lowest position, the stripper plate 32 abuts against the hoop material F and presses the hoop material F against the upper surface 47 of the die plate 40 in a state where it is displaced downward relative to the upper holder 12 with the compressive deformation of the stripper spring 29.

[0092] The vertical relative displacement stroke of the stripper 28 with respect to the upper holder 12 is greater than the penetration stroke of each of the punches 20, 22, 24 with respect to each of the dies 42, 44, 46. The penetration stroke is a stroke equivalent to the amount of penetration of each of the punches 20, 22, 24 into each of the dies 42, 44, 46 when the upper holder 12 is in the lowest position, as shown in Fig. 12A.

[0093] In other words, the stroke between the stripper 28 including the stripper plate 32's lowest position relative to the upper holder 12 and the position where the stripper 28 moves relative to the upper holder 12 with the elastic deformation of the stripper spring 29 to press the hoop material F against the upper surface 47 of the die plate 40 of the lower holder 14 is greater than the maximum entry stroke of the punches 20, 22, 24 entering each of the dies 42, 44, 46.

[0094] With this stroke setting, in the process of rising of the upper holder 12 after punching, after each of the punches 20, 22, 24 has come out of each of the dies 42, 44, 46 and the hoop material F, the stripper 28 rises together with the upper holder 12, and the pressing of the hoop material F by the stripper 28 is released. As a result, the state in which the hoop material F is pressed against the upper surface 47 of the die plate 40 by the stripper 28 is maintained until each of the punches 20, 22, 24 has come out of each of the dies 42, 44, 46.

[0095] As shown in Fig. 8A, each of stations II to VII except for the pilot hole punching station I is provided with a pilot pin 84 that can enter the pilot hole P of the hoop material F at each of stations II to VII. Note that the pilot pin 84 provided at the adhesive application station IV is not shown in Fig. 8B.

[0096] Each pilot pin 84 has, in that order in the axial direction, an upper end flange 84A, a straight shaft portion 84B, and a lower end tapered shaft portion 84C. Each pilot pin 84 is inserted into a mounting hole 86 formed in the upper holder 12 and passes vertically slidably through through holes 88 formed in the backing plate 16 and the punch plate 18 and a through hole 90 formed in the stripper 28, and in addition to the lower end tapered shaft portion 84C, the lower side of the straight shaft portion 84B protrudes downward from the underside 33 of the stripper plate 32 which is in the lowest position relative to the upper holder.

[0097] With this setting, during the descent of the upper holder 12, before the lower surface 33 of the stripper plate 32 abuts against the hoop material F, the straight shaft portion 84B of each pilot pin 84 enters the corresponding pilot hole P, and positioning is performed in the forward feed direction of the hoop material F and in the direction perpendicular to the forward feed direction of the hoop material F, i.e., in the left-right direction, on the upper surface 47 of the die plate 40.

[0098] Each pilot pin 84 is set to its lowest position (lowest limit position) by the lower surface of the upper end flange 84A abutting against the upper surface of the backing plate 16 that forms the bottom surface of the mounting hole 86, and is urged downward by the spring force of a compression coil spring 94 provided between the upper end flange 84A and a plug 92 fixed to the upper holder 12 to close the upper portion of the mounting hole 86. This spring urging structure is an escape structure that prevents damage to the pilot pin 84 when the pilot pin 84 does not enter the pilot hole P correctly. Note that the die plate 40 is formed with a pin escape hole 41 into which the pilot pin 84 enters.

[0099] Next, the feed guide structure and lift-up structure of the hoop material F will be described with reference to Figures 4, 8A and 8B. Left and right guide members 100 that guide the transfer of the hoop material F of the thin steel plate in the intermittent transfer direction (forward feed direction) of the hoop material F are attached symmetrically on the lower holder 14, which in the illustrated embodiment is on the die plate 40 fixed to the lower holder 14. The left and right guide members 100 are each long strip-shaped in the forward feed direction of the hoop material F, and as shown in Figure 4, are provided intermittently in the forward feed direction of the hoop material F except for the areas corresponding to stations II, IV and VI.

[0100] 16, the left and right guide members 100 have a lower surface 102 formed by a horizontal wall facing the upper surface 47 of the die plate 40 from above at a predetermined distance T, and a side surface 103 formed by a vertical wall facing the left and right end surfaces of the hoop material F at a predetermined gap, with the opposing sides having a hook-shaped cross section. The lower surface 102 and side surface 103 of the guide members 100 and the upper surface 47 of the die plate 40 cooperate with each other to define left and right guide grooves 104 of an inner opening having a rectangular cross section extending in the forward feed direction of the hoop material F.

[0101] As the left and right side edges of the hoop material F fit into the left and right guide grooves 104, each guide member 100 restricts the left-right movement of the hoop material F with its side surfaces 103 and restricts the upward movement of the hoop material F with its lower surfaces 102, thereby guiding the intermittent transport of the hoop material F.

[0102] This prevents the hoop material F from shifting left-right and up-down during intermittent transfer, and also restricts the hoop material F from moving left-right and upward from the upper surface 47 of the die plate 40 when adhesive is applied to the adhesive application surface (lower surface) of the hoop material F. This allows the adhesive to be applied accurately to the adhesive application surface. Note that downward movement of the hoop material F is restricted (prevented) by being placed on the upper surface 47 of the die plate 40, or by being lifted up by the lifter pins 110 described below.

[0103] The above-mentioned predetermined interval T is greater than the sum of the lift-up amount L of the hoop material F by the lifter pins 110 (described later) and the plate thickness of the hoop material F. With this setting, even when the hoop material F is lifted up by the lifter pins 110, the hoop material F does not come into contact with the lower surface 102 of the guide member 100. As a result, the upper surface of the hoop material F does not come into sliding contact with the lower surface 102 of the guide member 100 during intermittent transfer of the hoop material F, and the frictional resistance of the guide member 100 during intermittent transfer of the hoop material F is not increased.

[0104] 4, lifter pins 110 are provided at a predetermined interval on each of the left and right sides of the die plate 40 in the forward feed direction of the hoop material F. The positions of the lifter pins 110 overlap with the positions of the guide members 100 in a plan view.

[0105] 8A and 8B, each lifter pin 110 is provided in a lifter pin hole 112 formed in the die plate 40 and the lower holder 14 so as to open to the upper surface 47 of the die plate 40 so as to be displaceable in the vertical direction, and the upper end side is exposed on the upper surface 47 of the die plate 40. A lifter spring 114 made of a compression coil spring is provided between each lifter pin 110 and the bottom of each lifter pin hole 112. Each lifter spring 114 urges each corresponding lifter pin 110 upward.

[0106] Approximately half of the upper end surface of each lifter pin 110 contacts the lower surface of the hoop material F, and the remaining half can contact the stopper surface 106 formed on the guide member 100. As a result, when the hoop material F is not pressed down by the stripper 28, each lifter pin 110 is located at a raised position where the upper end surface contacts the stopper surface 106 due to the spring force of the lifter spring 114, and the hoop material F is lifted up from the upper surface 47 of the die plate 40, as shown in Figures 8A, 8B, and 16. When the hoop material F is pressed down by the stripper 28, each lifter pin 110 descends against the spring force of each lifter spring 114 by the hoop material F, as shown in Figures 11A, 11B, and 18, and the entire lifter pin 110 sinks into each lifter pin hole 112.

[0107] The amount of lift L of the hoop material F by the lifter pin 110 is determined by the upper surface of the lifter pin 110 abutting against the downward stopper surface 106 of the guide member 100, as shown in Figure 16, and the amount of lift L is set to a value greater than the applied thickness (maximum thickness) of the adhesive transferred to the underside of the hoop material F.

[0108] Next, the operation of the manufacturing apparatus 10 having the above-mentioned configuration will be described with reference to Figures 8A, 8B to 15A, 15B, and 16 to 19. Note that Figures 8A to 15A show the operation of the inner shape punching station II as a representative of each punching station, and Figures 8B to 15B show the operation of the adhesive application station IV. The operations of the pilot hole punching station I and the outer shape punching station VI are substantially the same as the operation of the inner shape punching station II, so a description of those operations will be omitted.

[0109] 8A and 8B show a state where the upper ram (not shown) of the press machine is at the top dead center and the upper holder 12 is at the most elevated position (top dead center position), as a press start state. In this press start state, the inner shape punching punch 22, the stripper 28, and the pilot pin 84 are in a position spaced above the die plate 40. The hoop material F is in a floating position (lifted up state) spaced from the upper surface 47 of the die plate 40 by the lifter pins 110 (see FIG. 16). In the lifted up state, the hoop material F is intermittently transferred in the forward feed direction by a predetermined amount at a time by an intermittent feed device (not shown) without the lower surface coming into sliding contact with the upper surface 47 of the die plate 40.

[0110] When one intermittent transfer is completed, or during the intermittent transfer process, the upper holder 12 starts to descend from the top dead center position, as shown in Figures 9A and 9B. As the upper holder 12 continues to descend, the straight shaft portion 84B, followed by the lower end tapered shaft portion 84C of each pilot pin 84, enters the pilot hole P of the hoop material F, as shown in Figures 10A and 10B, before the stripper 28 presses the hoop material F against the upper surface 47 of the die plate 40. This allows the hoop material F to be positioned in the transfer direction (forward feed direction) and left / right directions relative to the manufacturing apparatus 10.

[0111] This positioning is performed in a state where the hoop material F is lifted up from the upper surface 47 of the die plate 40, so that the movement of the hoop material F in the transfer direction and the left and right directions relative to the manufacturing device 10 for positioning is performed with low frictional resistance.

[0112] 11A and 11B, when the upper holder 12 continues to descend, the lower surface 33 of the stripper plate 32 comes into contact with the upper surface of the hoop material F (see FIG. 17), and the stripper 28, together with the lifter pins 110, pushes the hoop material F down against the spring force of the lifter springs 114 to a position where it comes into contact with the upper surface 47 of the die plate 40 (see FIG. 18). At this time, the overall spring force setting of the stripper springs 29 and the lifter springs 114 prevents the stripper springs 29 from being compressed and deformed, and the stripper 28 maintains its lowest position relative to the upper holder 12.

[0113] As the upper holder 12 continues to descend, as shown in Figures 12A and 12B, the stripper spring 29 is compressed and deformed while the upper holder 12 descends relative to the stripper 28, and the lower surface of the upper holder 12 is positioned at the bottom dead center where it abuts against the upper surface of the stopper 82. As a result, in the inner shape punching station II, as shown in Figure 12A, the inner shape punching punch 22 enters the inner shape punching die 44 in a clamped state in which the hoop material F is pressed against the upper surface 47 of the die plate 40 by the spring-biased stripper 28, and punching of the inner shape IS is performed. Also, in the adhesive application station IV, when the hoop material F is pressed against the upper surface 47 of the die plate 40 by the spring-biased stripper 28, the mounds N of the adhesive discharged from each discharge hole 64 are transferred to the corresponding application points E on the lower surface of the hoop material F (see Figure 7).

[0114] This transfer of adhesive is performed in a state where the left-right movement of the hoop material F is restricted by the guide member 100, the upward movement of the hoop material F is restricted, and the hoop material F is positioned by the pilot pin 84, so that even if the application points E are small, the transfer of adhesive to each application point E is performed accurately and with good positional precision.

[0115] Furthermore, because the adhesive is transferred in a state in which the hoop material F cannot vibrate when the bottom surface of the hoop material F is pressed against the top surface 47 of the die plate 40, even if punching of the inner shape IS and transfer of the adhesive are performed simultaneously, the adhesive is not transferred in a state in which the hoop material F is vibrating due to the punching impact in the inner shape punching station II, and the adhesive is accurately transferred to each application point E. As a result, even if the application points E are small, the adhesive is accurately transferred to each application point E with good positional precision.

[0116] When punching of the inner shape IS and transfer of the adhesive are completed, the upper holder 12 starts to rise from the bottom dead point, as shown in Figures 13A and 13B. When the upper holder 12 rises from the bottom dead point, first, the inner shape punching punch 22 comes out upward from the inner shape punching die 44. As described above, the stroke in which the stripper 28 moves relative to the upper holder 12 is greater than the maximum stroke in which the inner shape punching punch 22 enters the inner shape punching die 44, so that the hoop material F is maintained in a state in which it is pressed against the upper surface 47 of the die plate 40 by the stripper 28 until the inner shape punching punch 22 comes out of the inner shape punching die 44.

[0117] As a result, even if vibrations occur due to friction when the inner shape punching punch 22 escapes from the inner shape punching die 44 and the punching opening of the hoop material F, the vibrations will not be transmitted to the hoop material F at the adhesive application station IV, and the transferred shape of the adhesive transferred to the application point E of the hoop material F will not be distorted or scattered.

[0118] 14A and 14B, as the upper holder 12 continues to rise, the stripper 28 rises together with the upper holder 12, and each lifter pin 110 rises due to the spring force of the lifter spring 114, lifting up the hoop material F. As each lifter pin 110 abuts against the stopper surface 106, the hoop material F returns to a floating position (lifted-up state) away from the upper surface 47 of the die plate 40.

[0119] 19, the hoop material F is prevented from shifting left and right by the guide member 100, and the stripper 28 is in contact with the upper surface of the hoop material F and the lifter pins 110 are in contact with the lower surface of the hoop material F, so that the hoop material F is supported from above and below by the stripper 28 and the lifter pins 110. This prevents the hoop material F from shaking during the ascent process. This prevents the transfer shape of the adhesive transferred to the application point E of the hoop material F from collapsing or scattering during the ascent process (lift-up process).

[0120] When the upper holder 12 continues to rise, the pilot pin 84 comes out of the pilot hole P upward as shown in Figures 15A and 15B, and then the upper holder 12 returns to the top dead center position shown in Figures 8A and 8B. Intermittent transfer of the hoop material F begins at the point when the pilot pin 84 comes out of the pilot hole P. This intermittent transfer is performed in a state where the hoop material F is lifted up by the lifter pins 110 and the lower surface is separated from the upper surface 47 of the die plate 40 by the lift-up amount L (see Figure 16), so that the adhesive transferred to the application point E on the lower surface of the hoop material F is not rubbed by the upper surface 47 of the die plate 40.

[0121] This intermittent transfer is performed while the guide members 100 restrict the upward movement of the hoop material F and restrict the hoop material F from shifting left and right, so the transfer shape of the adhesive transferred to the application point E of the hoop material F does not collapse or scatter during the transfer process of the hoop material F. The intermittent transfer is completed before the next punching process begins.

[0122] As a result, the adhesive can be applied accurately to the adhesive-coated surface of the core thin plate W, and the adhesive applied to the adhesive-coated surface of the core thin plate W does not spread to the surrounding area, causing the transferred shape to collapse or scattering, thereby enabling the stable production of high-quality laminated cores, even for small laminated cores.

[0123] 20, the pilot hole P may be formed at a position directly below the pilot pin guide hole 108 formed through the guide member 100. In this case, the pilot pin 84 is accurately inserted into the pilot hole P while suppressing flapping of the hoop material F. In addition, since the pilot pin 84 (see FIG. 8A) penetrates the pilot pin guide hole 108 and enters the pilot hole P, the positioning accuracy of the hoop material F by the pilot pin 84 is improved.

[0124] Next, another embodiment of the laminated core manufacturing apparatus 10 will be described with reference to Figures 21, 22A, and 22B. In Figures 21, 21A, and 21B, parts corresponding to those in Figures 4, 8A, and 8B are given the same reference numerals as those in Figures 4, 8A, and 8B, and descriptions thereof will be omitted.

[0125] 21, in this embodiment, the guide member 100 is omitted, and the lifter pins 120 also serve as guide members for the hoop material F. The lifter pins 120 are provided on both the left and right sides of the die plate 40, with the lifter pins 110 being provided at a predetermined interval in the forward feed direction of the hoop material F.

[0126] 22A and 22B, each lifter pin 120 is provided in a lifter pin hole 122 formed in the die plate 40 and the lower holder 14 so as to open to the upper surface 47 of the die plate 40 so as to be displaceable in the vertical direction, and the upper end side protrudes above the upper surface 47 of the die plate 40. A lifter spring 124 made of a compression coil spring is provided between each lifter pin 120 and the bottom of each lifter pin hole 122. Each lifter spring 124 urges each corresponding lifter pin 110 upward. When the hoop material F is not pressed down by the stripper 28, each lifter pin 120 is located in an elevated position in which the step portion 120A abuts against a shoulder portion 116 provided at the joint between the die plate 40 and the lower holder 14 due to the spring force of the lifter spring 124, and when the hoop material F is pressed down by the stripper 28, each lifter pin 120 is located in a lowered position in which it has been lowered by the hoop material F against the spring force of each lifter spring 114.

[0127] Each lifter pin 120 has a circumferential groove 126 on the outer periphery of the portion protruding above the upper surface 47 of the die plate 40. Each circumferential groove 126 has a rectangular cross-sectional shape, similar to the guide groove 104 in the above embodiment, and the left and right side edges of the hoop material F enter the circumferential groove 126, thereby lifting the hoop material F above the upper surface 47 of the die plate 40 at the raised position, and placing the hoop material F on the upper surface 47 of the die plate 40 at the lowered position. In addition, the left and right side edges of the hoop material F enter the circumferential grooves 126 of the left and right lifter pins 120, so that each lifter pin 120 restricts the left and right movement of the hoop material F to guide the intermittent transfer of the hoop material F, and restricts the upward movement of the hoop material F during lift-up as well as the downward movement of the hoop material F.

[0128] This limits the left-right shifting of the hoop material F and the upward and downward movement of the hoop material F during intermittent transport of the hoop material F and when adhesive is applied to the adhesive application surface.This restriction prevents the hoop material F from flapping, and enables the adhesive to be accurately applied to the adhesive application surface.

[0129] This embodiment is substantially the same as the previously described embodiment except for the lift-up structure of the hoop material F by the lifter pins 120 described above, so that this embodiment can also obtain the same effects as the previously described embodiment.

[0130] In this embodiment, the lifter pins 120 also serve as guide members for the hoop material F, thereby reducing the number of parts.

[0131] Another embodiment of the laminated core manufacturing apparatus according to the present invention is as follows.

[0132] (1) A manufacturing apparatus for laminated iron cores, which is formed by stacking and bonding iron core sheets punched out into a predetermined shape from a strip of thin steel sheet, comprising an upper holder and a lower holder, a plurality of punches and dies provided on the upper holder and the lower holder, respectively, for successively punching out iron core sheets from the intermittently transported strip of thin steel sheet, a pilot pin provided on the upper holder and inserted into a pilot hole formed in the strip of thin steel sheet to position the strip of thin steel sheet at each transport position, and an adhesive application device provided on at least one of the upper holder and the lower holder for applying adhesive to an adhesive application surface of the strip of thin steel sheet in a portion corresponding to the iron core sheet.

[0133] (2) A manufacturing device for laminated cores, which is formed by stacking and bonding core sheets punched into a predetermined shape from a strip-shaped thin steel sheet, comprising an upper holder and a lower holder, a plurality of punches and dies provided on the upper holder and the lower holder, respectively, for successively punching core sheets from an intermittently transported strip-shaped thin steel sheet, a stripper plate provided on the upper holder so as to be displaceable in the vertical direction and having a lower surface facing an upper surface of the die, and an adhesive application device provided on at least one of the upper holder and the lower holder for applying adhesive to an adhesive application surface of a portion of the strip-shaped thin steel sheet corresponding to the core sheet. In this case, the manufacturing device for laminated cores may further comprise a stripper spring for biasing the stripper plate toward the lower holder, and the stripper plate may be configured so that the lower surface of the stripper plate is pressed against the upper surface of the die by the spring force of the stripper spring. Furthermore, the stripper plate may be configured so that the lower surface of the stripper plate presses the strip-shaped thin steel sheet against the upper surface of the die until the punch comes out of the die.

[0134] (3) A manufacturing apparatus for laminated iron cores, which is formed by stacking and bonding iron core sheets punched out into a predetermined shape from a strip of thin steel sheet, comprising an upper holder and a lower holder, a plurality of punches and dies provided on the upper holder and the lower holder, respectively, for successively punching out iron core sheets from the intermittently transported strip of thin steel sheet, a plurality of lifters provided on the lower holder so as to be displaceable in the vertical direction, for contacting the underside of the strip of thin steel sheet to separate the strip of thin steel sheet from the upper surface of the dies, and an adhesive application device provided on at least one of the upper holder and the lower holder for applying adhesive to the adhesive application surface of the strip of thin steel sheet in a portion corresponding to the iron core sheet. In this case, the stripper plate may further include a plurality of lifter springs that urge each of the lifters upwardly to move the strip of thin steel plate away from the upper surface of the die while the stripper plate and each of the lifters support the strip of thin steel plate from above and below when the stripper plate is raised.

[0135] The present invention has been described above with reference to its preferred embodiments. However, as will be easily understood by those skilled in the art, the present invention is not limited to such embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

[0136] For example, the adhesive (first adhesive liquid) application table 60 may be one that descends only during metering, or one that repeats descending and ascending in synchronization with the press operation. The application of the hardening accelerator or initiator (second adhesive liquid) may be continuous, or may be applied only when the hoop material F is stopped. The application of the hardening accelerator or initiator (second adhesive liquid) may be to the entire hoop material F or may be partial. A plurality of adhesive reservoirs 62 may be provided, and adhesive may be supplied from each adhesive reservoir 62 to the discharge holes 64 for each area. The supply of adhesive to the adhesive reservoirs 62 may be continuous, or may be intermittent in synchronization with the press operation. The application of adhesive is not limited to transfer, and may be spray application by a jet method. The application of adhesive to the hoop material F may be to the upper surface or both the lower and upper surfaces of the hoop material F. The application shape of the adhesive is not limited to a round dot shape, and may be annular, triangular, rectangular, irregular, etc.

[0137] Some types of laminated cores do not require inner punching, in which case the inner punching can be omitted. Also, pilot pin 84 is not essential. Laminated cores can have a planar shape of a square, T-shape, U-shape, etc. in addition to annular and circular shapes.

[0138] It is not necessary for the stripper plate 32 to press the hoop material F against the upper surfaces of the die plate 40, dies 44, 42, 46, and coating table 60, and the stripper plate 32 may limit the vertical displacement of the hoop material F between the die plate 40, dies 44, 46, and the upper surfaces of the coating table 60 until the punches 22, 24 come out of the dies 44, 46.

[0139] The stripper plate 32 and the lifter pins 110 may be arranged so that they are offset from each other in the left-right direction and do not overlap in a plan view, or they may be arranged so that they overlap in a plan view to sandwich the hoop material F from above and below. The lifter pins 110 may be arranged in the middle of the hoop material F in the left-right direction.

[0140] The adhesive application by the adhesive application device 50 is preferably performed immediately before the outer diameter punching process in consideration of the shorter transport distance of the hoop material F after the adhesive application, but it does not necessarily have to be performed immediately before the outer diameter punching process. The heating process and the rotation lamination process are not essential.

[0141] In addition, not all of the components shown in the above embodiment are necessarily essential, and may be appropriately selected without departing from the spirit of the present invention. For example, the pilot pin, guide member, and stripper structure are not essential, and may be omitted. [Explanation of symbols]

[0142] 10: Manufacturing equipment 12: Upper holder 13:Through hole 14: Lower holder 15: Spring chamber 16: Backing plate 17: Plug 18: Punch plate 20:Pilot hole punch 22: Punch for punching inner shape 24: Outer shape punch 26: Knockout 26A: Bottom end 26B: Upper flange 26C: Shaft 28: Stripper 29: Stripper spring 30: Stripper body 32: Stripper plate 33: Bottom surface 34: Punch hole 36: Punch hole 38: Punch hole 40: Die plate 41: Pin relief hole 42: Pilot hole punching die 44: Internal punching die 46: Outer shape punching die 47:Top surface 48: Discharge hole 50: Adhesive application device 52: Cam mechanism 54: Drive unit 56: Holding hole 58: Upper block 59: Lower block 60: Application table 61:Top surface 62: Adhesive reservoir 64:Discharge hole 66: Internal block 68: Adhesive supply passage 70: Adhesive supply tube 72: Adhesive supply device 74: Fixed cam 74A: Sawtooth section 74B: Sawtooth valley 76: Moving Cam 76A: Sawtooth section 76B: Sawtooth valley 82: Stopper 84: Pilot pin 84A: Upper flange 84B: Straight shaft 84C: Lower end tapered shaft 86: Mounting hole 88:Through hole 90:Through hole 92: Plug 94: Compression coil spring 100: Guide member 102: Bottom surface 103: Side 104: Guide groove 106: Stopper surface 108: Pilot pin guide hole 110: Lifter pin 112: Lifter pin hole 114: Lifter spring 116:Shoulder 120: Lifter pin 120A: Step 122: Lifter pin hole 124: Lifter spring 126: Peripheral groove I: Pilot hole punching station II: Internal punching station III: Idol Station IV: Glue application station V: Idol Station VI: Outer shape punching station VII: Idol Station T: Predetermined interval L: Lift-up amount A: Thin core plate W: Thin core plate M: Laminated core F: Hoop material (thin steel strip) E: Application point E1: Application point E2: Application point G: Core thin plates

Claims

[Claim 1] A laminated core manufacturing apparatus for laminating and bonding thin iron core plates punched into a predetermined shape from an intermittently transported strip-shaped thin steel plate, comprising: An upper holder and a lower holder; an adhesive application device provided on at least one of the upper holder and the lower holder, which applies adhesive to an adhesive application surface of the intermittently transferred strip-shaped thin steel plate at a portion corresponding to the iron core thin plate; a pilot pin provided on the upper holder and inserted into a pilot hole formed in the strip of steel plate to position the strip of steel plate at each transfer position; A die plate provided in the lower holder; a stripper plate that is provided on the upper holder so as to be displaceable in the vertical direction, has a lower surface facing the upper surface of the die plate, and presses the strip-shaped thin steel plate, which is at an adhesive application position by the adhesive application device, against the upper surface of the die plate; and left and right guide members provided on the lower holder for guiding the transfer of the strip-shaped thin steel plate in the intermittent transfer direction and limiting the upward movement of the strip-shaped thin steel plate, A laminated core manufacturing apparatus, in which pilot pin guide holes are formed through the left and right guide members, and the pilot pins are arranged to pass through the pilot pin guide holes and enter the pilot holes formed in the strip-shaped thin steel plate.

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