Method and device for manufacturing laminated iron core

Abstract

To provide a method for manufacturing a laminated iron core capable of easily and surely absorbing plate thickness deviation of an iron core piece in the laminated iron core.SOLUTION: A plurality of iron core pieces 7 are coaxially laminated while interposing adhesive 19 applied to a plurality of positions in a circumferential direction between them. An application amount of the adhesive 19 at the plurality of positions is adjusted between adjacent iron core pieces 7 in accordance with change in a plate thickness in a circumferential direction of the adjacent iron core pieces 7. A height in an axial direction based on the application amount is set to decrease as a plate thickness increases, and a height relation in the axial direction is held when the plurality of iron core pieces 7 are laminated.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a laminated core used in a rotating electrical machine.

Background Art

[0002] As a conventional method for manufacturing a laminated core, there is one in which a plurality of disk-shaped core pieces are laminated to manufacture a laminated core. Since the plate thickness of each core piece is not strictly constant in the circumferential direction, it has a change (plate thickness deviation) in the circumferential direction of the plate thickness. Therefore, when laminating a plurality of core pieces, the plate thickness deviation is absorbed by changing the phase of the core pieces.

[0003] On the other hand, Patent Document 1 discloses a method for manufacturing a laminated core that absorbs a plate thickness deviation while laminating a plurality of core pieces without changing the phase.

[0004] In this manufacturing method, a filamentous thermoplastic resin is partially disposed between core members that are core pieces, and the core members are laminated. Then, the laminated core members are pressed and heated to melt the thermoplastic resin. At this time, since the thermoplastic resin is divided into a portion where it melts thinly in a film shape and a portion where it melts relatively thickly, the plate thickness deviation can be absorbed.

[0005] However, in the manufacturing method of Patent Document 1 above, since a plurality of core members are laminated with a thermoplastic resin interposed therebetween, the lamination is laborious. Further, it is difficult to control the molten state of the thermoplastic resin, and the absorption accuracy of the plate thickness deviation is low.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved was that it was difficult to easily and surely absorb the plate thickness deviation of the core pieces in the laminated core.

Means for Solving the Problem

[0008] The present invention stacks a plurality of core pieces coaxially with an adhesive applied at a plurality of circumferential positions between adjacent core pieces interposed therebetween, and the adhesives at the plurality of positions are adjusted in application amount according to the change in the plate thickness in the circumferential direction of at least one of the adjacent core pieces, and the axial height based on the application amount is set to decrease as the plate thickness increases, and provides a method for manufacturing a laminated core in which the axial height relationship is maintained when the plurality of core pieces are laminated.

[0009] Further, the present invention provides an adhesive application device for applying an adhesive to a plurality of circumferential positions of a core piece portion that becomes a core piece to a steel plate, a punch for punching out the core piece portion from the steel plate as the core piece, and a die for sequentially holding the core pieces punched out by the punch and laminating a plurality of core pieces coaxially with the adhesive interposed therebetween, and the adhesives at the plurality of positions are adjusted in application amount according to the change in the plate thickness in the circumferential direction of at least one of the adjacent core pieces, and the axial height based on the application amount is set to decrease as the plate thickness increases, and provides a manufacturing apparatus for a laminated core in which the axial height relationship is maintained when the plurality of core pieces are laminated.

Advantages of the Invention

[0010] According to the present invention, it is possible to easily and surely absorb the plate thickness deviation of the core pieces in the laminated core.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0012] The object of easily and surely absorbing the plate thickness deviation of the core pieces in the laminated core is achieved by adjusting the application amount of the adhesive according to the plate thickness change of at least one of the adjacent core pieces among the adjacent core pieces.

[0013] That is, in the method for manufacturing the laminated core 1, a plurality of core pieces 7 are laminated coaxially with an adhesive 19 applied at a plurality of circumferential positions therebetween.

[0014] The adhesives 19 at a plurality of locations are adjusted in application amount between adjacent core pieces 7 in correspondence with the change in the plate thickness in the circumferential direction of the adjacent core pieces 7, and are set such that the axial height based on the application amount decreases as the plate thickness increases, and the axial height relationship is maintained when the plurality of core pieces 7 are laminated.

[0015] The plurality of core pieces 7 may be laminated via the adhesive 19, and the lamination method is not limited, but it is preferable to laminate them by punching them sequentially into the die 29 by the punch 25 and holding them.

[0016] In this case, based on the holding force of the die 29 for each core piece 7 and the shape holding force of the adhesive 19, it is possible to hold the height relationship of the adhesive 19 at a plurality of locations.

[0017] In the method for manufacturing the laminated core 1, it is preferable to measure the thickness of the steel sheet 5 and specify the thickness of the portion of the core piece part 5a to be punched out as the core piece 7 where the adhesive 19 is to be applied. In this case, the adhesive 19 is applied in an amount corresponding to the specified thickness for the planned location. Then, the core piece part 5a coated with the adhesive 19 is punched out from the steel sheet 5 as the core piece 7 and laminated while interposing the adhesive 19 on the core piece 7 held in the die 29.

[0018] The punch 25 has a flat surface at its tip that is orthogonal to the axial direction, and each core piece 7 is held in the die 29 in a state where one axial side surface 7a that abuts against the tip of the punch 25 during punching is along the tip of the punch 25, and the next core piece 7 may be laminated on the one side surface 7a with the adhesive 19 interposed therebetween.

[0019] The application of the adhesive 19 and the punching of the core pieces 7 may be sequentially performed while feeding the steel sheet 5. In this case, the adhesive 19 can be applied to the same location according to the feed of the steel sheet 5 by a plurality of discharge portions 15a arranged in the feed direction of the steel sheet 5, and the application amount is set by the number of application times to the same location of the steel sheet 5.

[0020] As another embodiment, the application of the adhesive 19 may be performed on different locations of the steel sheet 5 by a plurality of discharge portions 15a arranged in the feed direction of the steel sheet 5.

[0021] The manufacturing apparatus 3 for the laminated core includes an adhesive application apparatus 15, a punch 25, and a die 29.

[0022] Next, the adhesive application device 15 applies the adhesive 19 to a plurality of circumferential locations of the core piece portion 5a that becomes the core piece 7 with respect to the steel plate 5. The punch 25 punches out the core piece portion 5a as the core piece 7 from the steel plate 5. The die 29 sequentially holds the core pieces 7 punched out by the punch 25, and stacks the plurality of core pieces 7 coaxially with the adhesive 19 interposed therebetween.

[0023] The manufacturing apparatus 3 may include a plate thickness specifying unit 11 that measures the plate thickness of the steel plate 5 and specifies the plate thickness of the planned location where the adhesive 19 is to be applied in the core piece portion 5a. In this case, the adhesive application device 15 applies the adhesive 19 with an application amount corresponding to the specified plate thickness to the planned location.

[0024] The punch 25 may have a flat surface at its tip that is orthogonal to the axial direction. In this case, each core piece 7 is held in the die 29 with one axial side surface 7a that abuts against the tip of the punch 25 during punching along the tip of the punch 25, and the next core piece 7 is stacked on the one side surface 7a with the adhesive 19 interposed therebetween.

[0025] The manufacturing apparatus 3 may include a feeding device 9 that sequentially performs the application of the adhesive 19 and the punching of the core pieces 7 while feeding the steel plate 5.

[0026] In this case, the adhesive application device 15 includes a plurality of discharge portions 15a arranged in the feeding direction of the steel plate 5 and capable of applying to the same location, and the application amount may be set by the number of application times to the same location.

[0027] As another embodiment, the adhesive application device 15 may include a plurality of discharge portions 15a arranged in the feeding direction of the steel plate 5 and applying the adhesive 19 to different locations of the steel plate 5.

[0028] Also, the adhesive application device 15 may apply the adhesive 19 by an inkjet method, regardless of the application method of the adhesive 19.

Example

[0029] [Manufacturing Apparatus for Laminated Core] FIG. 1 is a schematic side view showing a cross section of a part of a laminated core manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 2 is a plan view showing a steel sheet on which punching is performed by the manufacturing apparatus of FIG. 1.

[0030] The manufacturing apparatus 3 for the laminated core 1 in FIG. 1 manufactures a laminated core, which is a core of a rotating electric machine such as an electric motor or a generator. The laminated core 1 may be a stator core or a rotor core. In this manufacturing apparatus 3, a plurality of disc-shaped core pieces 7 are sequentially punched out from a steel sheet 5, which is an electromagnetic steel sheet or a silicon steel sheet supplied intermittently, and laminated to form the laminated core 1.

[0031] The manufacturing apparatus 3 of the present embodiment includes a feeding device 9, a plate thickness measuring device 11, a die device 13, an adhesive coating device 15, and a control unit 17.

[0032] The feeding device 9 intermittently feeds the steel sheet 5. The feeding device 9 can have an appropriate configuration, but in the present embodiment, it includes a pair of feeding rollers 9a. The feeding rollers 9a feed the steel sheet 5 by rotating while sandwiching the steel sheet 5 therebetween. The driving of the feeding rollers 9a is performed by a servo motor or the like (not shown).

[0033] The plate thickness measuring device 11 measures the plate thickness of the steel sheet 5. The plate thickness measuring device 11 is located upstream of the die device 13 in the feeding direction of the steel sheet 5. However, the plate thickness measuring device 11 may be arranged at an arbitrary position as long as it can measure the plate thickness of the steel sheet 5 before the application of the adhesive 19.

[0034] The plate thickness measuring device 11 of the present embodiment has a plurality of measuring portions 11a along the width direction orthogonal to the feeding direction of the steel sheet 5. Each measuring portion 11a is composed of, for example, a laser displacement meter. However, the method of measuring the plate thickness is not limited.

[0035] The dimension of the plate thickness measuring device 11 in the width direction is larger than the outer diameter of the core piece portion 5a punched out as the core piece 7, as shown in FIG. 2. This enables the measurement of the plate thickness at a plurality of measurement locations 5b across the outer diameter of the core piece portion 5a.

[0036] Therefore, in this embodiment, it is possible to measure the thickness of the core piece portion 5a as a whole according to the feeding of the steel sheet 5, and directly measure and specify the thickness of the planned location where the adhesive 19 is to be applied in the core piece portion 5a. The thickness measuring device 11 constitutes the thickness specifying portion of this embodiment.

[0037] Note that the thickness measuring unit 11a may measure the thickness for each predetermined span of the steel sheet 5, for example. In this case, for example, the control unit 17 or the like may function as the thickness specifying portion and predict the thickness of the planned location of the core piece portion 5a from the measured thickness without directly measuring it. Further, the thickness measurement may be performed only on a part of the core piece portion 5a, and the remaining parts may be treated as having the same thickness as the measured core piece portion 5a without performing the thickness measurement.

[0038] The die device 13 in FIG. 1 includes an upper die 21 and a lower die 23. The upper die 21 is configured to be movable up and down with respect to the lower die 23, and performs punching by the punch 25 when descending. The punch 25 is provided to protrude downward from the upper die 21, and the tip thereof passes through the stripper plate 27. The tip of the punch 25 is constituted by a flat surface along the width direction and the feeding direction orthogonal to the vertical direction (see FIG. 4).

[0039] The stripper plate 27 is supported by a biasing member such as a spring with respect to the upper die 21, and is movable toward the upper die 21 against the biasing force. When the upper die 21 descends, the stripper plate 27 comes into contact with the steel sheet 5. In this state, when the upper die 21 further descends, the punch 25 protrudes with respect to the stripper plate 27 to perform punching.

[0040] The punch 25 of the upper die 21 includes a first punch 25a for inner periphery punching that punches the inner periphery of the core piece 7 in FIG. 2 and a second punch 25b for outer periphery punching that punches the outer periphery of the core piece 7 in FIG. 2.

[0041] The first punch 25a for inner periphery punching is located upstream of the adhesive applicator 15 in the feeding direction of the steel plate 5, and the second punch 25b for outer periphery punching is located downstream of the adhesive applicator 15 in the feeding direction of the steel plate 5. Note that the first punch 25a for inner periphery punching may be located downstream of the adhesive applicator 15 in the feeding direction of the steel plate 5.

[0042] In such a punch 25, after the inner periphery of the core piece portion 5a is punched by the first punch 25a, when the outer periphery of the core piece portion 5a is punched by the second punch 25b, the core piece portion 5a will be punched out from the steel plate 5 as the core piece 7. The punched core piece 7 is held in the die 29 of the lower die 23 as it is.

[0043] The lower die 23 is composed of a first lower die 23a for inner periphery punching and a second lower die 23b for outer periphery punching. The first lower die 23a is arranged corresponding to the first punch 25a for inner periphery punching of the upper die 21 and is provided with a die for inner periphery punching (not shown). This first lower die 23a performs inner periphery punching in cooperation with the first punch 25a.

[0044] The second lower die 23b is arranged corresponding to the second punch 25b for outer periphery punching of the upper die 21 and is provided with an outer periphery punching die 29. This second lower die 23b performs outer periphery punching in cooperation with the second punch 25b and punches out and holds the core piece 7.

[0045] The die 29 of this embodiment includes a die main body portion 29a and a squeeze ring 29b.

[0046] The die main body portion 29a is formed in a ring shape and is fixed to the inner periphery of the support hole 23ba of the second lower die 23b. The squeeze ring 29b is arranged adjacent to the die main body portion 29a in the punching direction of the core piece 7 and is supported by the inner periphery of the support hole 23ba in the same manner as the die main body portion 29a. The squeeze ring 29b is formed in a ring shape that is longer than the die main body portion 29a in the punching direction.

[0047] Note that the punching direction coincides with the axial direction of the core piece 7, and is the vertical direction in this embodiment. However, the punching direction and the axial direction do not necessarily have to be the vertical direction.

[0048] This squeeze ring 29b is a portion that applies and holds side pressure by pressing the punched core pieces 7 from the outer periphery. It is also possible to omit the squeeze ring 29b. In this case, the die main body portion 29a may be extended in the punching direction, or the diameter of the support hole 23ba of the lower die 23 may be reduced to provide the function of the squeeze ring 29b.

[0049] Within the squeeze ring 29b, the stacked core 1 is formed by stacking a predetermined number of held core pieces 7 with an adhesive 19 interposed therebetween. Note that a block having a stacking height lower than that of the stacked core 1 may be formed. The blocks are stacked to form the stacked core 1. The plurality of core pieces 7 constituting the stacked core 1 are stacked coaxially without different phases.

[0050] When stacking the core pieces 7, although details will be described later, the adhesive 19 absorbs the thickness deviation, which is a change in the plate thickness in the circumferential direction of the core piece 7.

[0051] The adhesive application device 15 in FIG. 1 applies the adhesive 19 to a plurality of locations (predetermined locations) in the circumferential direction of the core piece portion 5a of the steel plate 5 as shown in FIG. 2. This adhesive application device 15 is disposed between the first lower die 23a and the second lower die 23b of the lower die 23. However, the adhesive application device 15 may be positioned upstream of the steel plate 5 in the feeding direction with respect to the die device 13.

[0052] The adhesive application device 15 of this embodiment includes a discharge portion 15a that is supported so as to be vertically movable below the steel plate 5. The discharge portion 15a applies the adhesive 19 held at its tip to a plurality of locations on the lower surface of the steel plate 5.

[0053] The adhesive 19 is constantly supplied to the tip of the discharge part 15a, for example, and is held by its viscosity or the like. In this embodiment, a plurality of discharge parts 15a are arranged in a ring corresponding to the locations where the adhesive in the core piece part 5a is to be applied. Each discharge part 15a is configured such that the application amount can be controlled, for example, by adjusting the supply amount of the adhesive 19 to the tip. However, various configurations of the discharge part 15a can be adopted.

[0054] The material of the adhesive 19 is not particularly limited, and various adhesives such as thermosetting, anaerobic, and ultraviolet curable adhesives can be adopted. The shape retention force of this adhesive 19 is set by its viscosity and thixotropy. The shape retention force refers to the ability to retain the shape when applied.

[0055] The control unit 17 is an information processing device having a processor, a memory, and the like, and controls each part of the manufacturing apparatus 3. By this control, the manufacturing method of the laminated core 1 of this embodiment is realized. Note that the control unit 17 may be not only a single information processing device but also a combination of a plurality of information processing devices.

[0056] [Manufacturing Method of Laminated Core] Hereinafter, the manufacturing method of the laminated core 1 will be described together with the operation of the manufacturing apparatus 3. In this embodiment, the case of laminating the disk-shaped core pieces 7 will be described, but the manufacturing method of the laminated core 1 is also applicable to those obtained by dividing the laminated core 1 as in the known techniques described in the prior art.

[0057] In the manufacturing method of the laminated core 1 of this embodiment, as shown in FIGS. 1 and 2, the plate thickness of the steel plate 5 is measured by the plate thickness measuring device 11. Based on this plate thickness, the plate thickness of the location where the adhesive 19 is to be applied in the core piece part 5a to be punched out as the core piece 7 is specified. In this embodiment, the plate thickness of the planned location is specified by directly measuring the plate thickness of the planned location with the plate thickness measuring device 11.

[0058] The core piece portion 5a where the plate thickness has been measured is supplied to the die device 13 by feeding the steel plate 5. In the die device 13, first, the inner circumference of the core piece portion 5a of the steel plate 5 is punched by the first punch 25a.

[0059] The core piece portion 5a with the inner circumference punched is supplied to the adhesive application device 15 by feeding the steel plate 5. The adhesive application device 15 applies the adhesive 19 in an application amount corresponding to the specified plate thickness to the planned application locations of the adhesive 19 on the core piece portion 5a. The application amount is the volume of the adhesive 19 in one piece. With this application amount, it is sufficient for the adhesive 19 to have a height corresponding to the specified plate thickness.

[0060] In addition, in this embodiment, the application locations of the adhesive 19 are multiple locations in the circumferential direction. For the lowermost core piece 7 of the laminated core 1, the application of the adhesive 19 is omitted.

[0061] FIG. 3 is a schematic side view showing the core piece portion 5a to which the adhesive 19 has been applied.

[0062] As shown in FIG. 3, the application amount of the adhesive 19 is less for locations with a large plate thickness and greater for locations with a small plate thickness. Based on this application amount, the axial height of the adhesive 19 will be different. That is, the height of the adhesive 19 with a large application amount will be relatively high, and the height of the adhesive 19 with a small application amount will be relatively low. The height of the adhesive 19 is the height from the lower surface of the steel plate 5 where the adhesive 19 is applied.

[0063] FIGS. 4(A) to (C) are schematic cross-sectional views showing the punching and lamination of the core piece 7. Note that the cross-sectional view in FIG. 4 shows a cross-section along the width direction of the steel plate 5.

[0064] The core piece portion 5a to which the adhesive 19 has been applied is supplied between the second punch 25b of the upper die 21 and the die 29 of the second lower die 23b by feeding the steel plate 5 as shown in FIG. 4(A). Then, as shown in FIG. 4(B), the outer circumference of the core piece portion 5a is punched by the second punch 25b, and the core piece portion 5a is punched out from the steel plate 5 as the core piece 7.

[0065] The punched core pieces 7 are held as they are in the die 29 of the second lower die 23b, and are laminated with an adhesive 19 interposed therebetween on the core pieces 7 held in the die 29 that have been punched previously. At this time, the core pieces 7 punched including the preceding core pieces 7 are held in the die 29 in a state where the upper surface 7a (one axial side surface) that contacts the tip of the second punch 25b during punching is along the tip of the second punch 25b (in a state along the width direction and the feed direction).

[0066] For this reason, between adjacent core pieces 7, the gap 31 will vary axially according to the change in the plate thickness of the upper core piece 7, which is the other, with respect to the upper surface 7a of the lower core piece 7, which is one.

[0067] The adhesives 19 at a plurality of circumferential locations positioned in this gap 31 have their application amounts adjusted according to the change in the plate thickness of the upper core piece 7 (change in the gap 31), and the height of the adhesive 19 based on the application amount is high at the portion with a small plate thickness (the portion with a large gap 31) and low at the portion with a large plate thickness (the portion with a small gap 31).

[0068] Such a height relationship of the adhesive 19 is maintained even when the core pieces 7 are laminated. It is preferable to strictly maintain the height relationship of the adhesive 19, but it does not have to be strict. For example, although the adhesives 19 at a plurality of locations tend to be crushed axially when the core pieces 7 are laminated, the magnitude relationship of the heights is maintained even if the amounts of crushing are different.

[0069] The maintenance of the height relationship of the adhesive 19 can be adjusted by the holding force of the die 29 on the core pieces 7 and the shape holding force of the adhesive 19. The holding force of the die 29 is set by the side pressure based on the inner diameter of the die 29, and the shape holding force of the adhesive 19 is adjusted by the viscosity, thixotropy, etc. of the adhesive 19.

[0070] Therefore, the upper iron core piece 7 is filled and held by the adhesive 19 for the change in the gap 31 with respect to the upper surface 7a of the lower iron core piece 7, and the upper surface 7a can maintain the state along the width direction and the feed direction. For this reason, the stacked iron core pieces 7 have their upper surfaces 7a held in the width direction and the feed direction.

[0071] Similarly, by performing a series of operations such as plate thickness measurement, inner circumference punching, application of the adhesive 19, punching and holding of the iron core piece 7, the iron core piece 7 is further stacked as shown in FIG. 4(C). Thus, by repeating the series of operations, a plurality of iron core pieces 7 can be stacked to obtain the laminated iron core 1.

[0072] FIGS. 5(A) to (C) are schematic cross-sectional views showing punching and stacking of the iron core piece 7 according to the comparative example.

[0073] In the comparative example, as shown in FIGS. 5(A) to (C), the application amounts of the adhesive 19 at a plurality of locations in the circumferential direction with respect to the iron core piece 7 are made constant. Other than that, it is the same as in the first embodiment.

[0074] In such a comparative example, when stacking the iron core pieces 7, the change in the gap 31 between adjacent iron core pieces 7 is not maintained, and a uniform gap 31 is formed. Accordingly, the upper surface 7a of the lower iron core piece 7 inclines along the lower surface 7b of the upper iron core piece 7. In this state, the next iron core piece 7 is stacked on the upper surface 7a of the upper iron core piece 7 with a uniform gap 31.

[0075] As a result, the upper surface 7a of the upper iron core piece 7 inclines along the lower surface 7b of the next iron core piece 7 (the uppermost iron core piece 7), and the upper surface 7a of the further lower iron core piece 7 also inclines. Therefore, as the iron core pieces 7 are stacked based on the plate thickness deviation of the iron core pieces 7, the inclination of the upper surface 7a gradually increases, and the cumulative error increases.

[0076] On the other hand, in the present embodiment, as described above, since the upper surfaces 7a of the plurality of iron core pieces 7 are held in the width direction and the feed direction, the plate thickness deviation is absorbed and the cumulative error can be suppressed.

[0077] Thus, in this embodiment, the adhesive 19 can be used to easily and surely absorb the plate thickness deviation of the core piece 7 in the laminated core 1.

[0078] The adhesives 19 at a plurality of locations are held in a height relationship based on the holding force of the die 29 for each core piece 7 and the shape holding force of the adhesive 19. Therefore, just by holding and laminating the plurality of core pieces 7 on the die 29, the plate thickness deviation can be easily and surely absorbed.

[0079] In this embodiment, the plate thickness of the steel plate 5 is measured to identify the plate thickness of the planned location where the adhesive 19 is to be applied in the core piece portion 5a punched out as the core piece 7, and the adhesive 19 is applied in an amount corresponding to the identified plate thickness to the planned location. Then, the core piece portion 5a coated with the adhesive 19 is punched out from the steel plate 5 as the core piece 7 and laminated on the core piece 7 held in the die 29 with the adhesive 19 interposed therebetween.

[0080] Therefore, the plate thickness deviation of the core piece 7 can be more easily and surely absorbed.

[0081] Also, in this embodiment, each core piece 7 is held in the die 29 with the upper surface 7a that abuts against the tip of the punch 25 during punching in a state along the tip of the punch 25, and the next core piece 7 is laminated on the upper surface 7a with the adhesive 19 interposed therebetween.

[0082] Therefore, in this embodiment, the cumulative error can be suppressed while more surely absorbing the plate thickness deviation of each core piece 7.

[0083] Note that the application of the adhesive 19, the punching of the core piece 7, and the lamination are performed in a series of steps in the manufacturing apparatus 3, but they may be performed in separate steps. For example, a plurality of core pieces 7 may be punched out in advance, the plate thickness of these core pieces 7 may be measured separately, and the adhesive 19 may be applied based on the measurement results to laminate the plurality of core pieces 7.

Embodiment

[0084] FIG. 6 is a schematic plan view showing a discharge part of an adhesive applicator used in the manufacturing apparatus according to Embodiment 2 of the present invention. In Embodiment 2, since the basic configuration is common to that of Embodiment 1, corresponding components are denoted by the same reference numerals and redundant explanations are omitted. For the overall configuration of Embodiment 2, refer to FIG. 1.

[0085] In the manufacturing apparatus 3 of the present embodiment, the adhesive applicator 15 has a plurality of discharge parts 15a arranged in a row in the width direction and a plurality of rows (two rows) arranged side by side in the feeding direction. Therefore, the adhesive applicator 15 has a plurality of discharge parts 15a in the width direction and the feeding direction. Note that the number of rows of the protruding parts 15a can be arbitrarily set.

[0086] The plurality of discharge parts 15a arranged in the feeding direction enable the adhesive to be applied to the same location on the steel plate 5 one or more times according to the feeding of the steel plate 5. Then, the application amount of the adhesive 19 is set according to the number of application times to the same location.

[0087] Thereby, while simplifying the structure by making each discharge part 15a have the same configuration, the application amount of the adhesive 19 can be easily adjusted.

[0088] Also, in Embodiment 2, the adhesive 19 can be applied to different locations on the steel plate 5 by the plurality of discharge parts 15a. In this case, continuous application can be performed at time intervals shorter than the minimum time during which each discharge part 15a can perform continuous application.

[0089] [Modification Example] FIG. 7 is a schematic plan view showing a discharge part of an adhesive applicator used in the manufacturing apparatus according to a modification example of Embodiment 2.

[0090] In the modification example of FIG. 7, a plurality of discharge parts 15a arranged in a row in the width direction are arranged in a plurality of rows (two rows) side by side in the feeding direction, and the plurality of discharge parts 15a in different rows are shifted in the width direction.

[0091] In such a modification, the coating interval in the width direction can be made narrower. In addition, in the modification, as in Example 2, the adhesive 19 can be applied to different portions of the steel plate 5, and continuous coating can be performed at a time interval shorter than the minimum time required for continuous coating of each discharge portion 15a.

Example

[0092] FIGS. 8(A) and 8(B) are schematic cross-sectional views showing the discharge portion of the adhesive coating device used in the manufacturing apparatus according to Example 3 of the present invention. FIG. 8(A) shows the non-injection of the adhesive, and FIG. 8(B) shows the injection of the adhesive. In Example 3, since the basic configuration is common to Example 1, the corresponding configurations are denoted by the same reference numerals and redundant descriptions are omitted. For the overall configuration of Example 3, refer to FIG. 1.

[0093] In the manufacturing apparatus 3 of the present example, the discharge portion 15a of the adhesive coating device 15 is of an inkjet type. Otherwise, it is the same as in Example 1.

[0094] That is, the discharge portion 15a includes a hollow head portion 33 and a piezoelectric element 35. The head portion 33 has a storage portion 33a for storing the adhesive 19 in its hollow interior. The storage portion 33a communicates with the injection port 33b of the adhesive 19, and supplies the adhesive 19 to the injection port 33b by the operation of the piezoelectric element 35.

[0095] The piezoelectric element 35 is disposed so as to close the opening 33c provided in the head portion 33 and faces the storage portion 33a. When a voltage is applied to this piezoelectric element 35, it displaces into the storage portion 33a. Due to this displacement, the volume of the storage portion 33a decreases, and the surplus adhesive 19 is supplied to the injection port 33b and injected.

[0096] Note that the discharge portion 15a may be of an inkjet type, and may use something other than the piezoelectric element 35.

[0097] In this embodiment, in addition to the effects of Embodiment 1, the application amount of the adhesive 19 can be easily adjusted. Further, in this embodiment, the time responsiveness and high speed of the application of the adhesive 19 by the adhesive application device 15 can be improved.

Explanation of Reference Numerals

[0098] 1 Laminated core 3 Manufacturing apparatus 5 Steel plate 5a Core piece portion 7 Core piece 7a Upper surface 9 Feeding device 11 Plate thickness measuring device 15 Adhesive application device 15a Discharge portion 19 Adhesive 25 Punch 29 Die 31 Gap

Claims

1. A method for manufacturing a laminated core, comprising coaxially laminating a plurality of core pieces with an adhesive applied at a plurality of circumferential positions between adjacent core pieces interposed therebetween, wherein the amounts of the adhesive applied at the plurality of positions are adjusted according to the change in the plate thickness in the circumferential direction of at least one of the adjacent core pieces, and the axial height based on the amount of the adhesive applied is set to decrease as the plate thickness increases, and the axial height relationship is maintained when the plurality of core pieces are laminated. A method for manufacturing a laminated core.

2. A method for manufacturing a laminated core according to Claim 1, wherein the plurality of core pieces are laminated by sequentially punching and holding them in a die from a steel plate by a punch. A method for manufacturing a laminated core.

3. A method for manufacturing a laminated core according to Claim 2, wherein the axial height relationship is maintained based on the holding force of each core piece in the die and the shape holding force of the adhesive for the plurality of positions of the adhesive. A method for manufacturing a laminated core.

4. A method for manufacturing a laminated core according to Claim 2, wherein the thickness of the steel plate is measured to identify the plate thickness at a planned location where the adhesive is to be applied in the core piece portion punched out as the core piece, the adhesive is applied to the planned location in an amount corresponding to the identified plate thickness, and the core piece portion with the adhesive applied is punched out from the steel plate as the core piece and laminated on the core piece held in the die with the adhesive interposed therebetween. A method for manufacturing a laminated core.

5. A method for manufacturing a laminated core according to Claim 2, wherein the punch has a flat surface at its tip that is perpendicular to the axial direction, each core piece is held in the die with one axial side surface that abuts against the tip of the punch during punching along the tip of the punch, and the next core piece is laminated on the one side surface with the adhesive interposed therebetween. A method for manufacturing a laminated core.

6. A method for manufacturing a laminated core according to Claim 2, wherein the adhesive application and the punching of the core pieces are sequentially performed while feeding the steel plate, the adhesive can be applied to the same location according to the feeding of the steel plate by a plurality of discharge portions arranged in the feeding direction of the steel plate, and the amount of the adhesive applied is set by the number of times of application to the same location of the steel plate. A method for manufacturing a laminated core.

7. A method for manufacturing a laminated core according to Claim 2, wherein the adhesive application and the punching of the core pieces are sequentially performed while feeding the steel plate. The application of the adhesive is performed on different locations of the steel plate by a plurality of discharge parts arranged in the feeding direction of the steel plate. Method for manufacturing a laminated core.

8. An adhesive application device for applying an adhesive to a plurality of circumferential locations of a core piece portion that becomes a core piece with respect to a steel plate, a punch for punching out the core piece portion from the steel plate as the core piece, and a die for sequentially holding the core pieces punched out by the punch and laminating a plurality of core pieces coaxially with the adhesive interposed therebetween. The adhesives at the plurality of locations are adjusted in application amount according to the change in plate thickness in the circumferential direction of at least one of the adjacent core pieces between the adjacent core pieces, and are set such that the axial height based on the application amount decreases as the plate thickness increases, and the axial height relationship is maintained when the plurality of core pieces are laminated. Manufacturing apparatus for a laminated core.

9. A manufacturing apparatus for a laminated core according to Claim 8, wherein the adhesives at the plurality of locations maintain the height relationship based on the holding force of the die for each core piece and the shape holding force of the adhesive. Manufacturing apparatus for a laminated core.

10. A manufacturing apparatus for a laminated core according to Claim 8, comprising a plate thickness specifying part for measuring the plate thickness of the steel plate and specifying the plate thickness of a planned location where application of the adhesive in the core piece portion is planned, wherein the adhesive application device applies the adhesive at an application amount corresponding to the specified plate thickness to the planned location. Manufacturing apparatus for a laminated core.

11. A manufacturing apparatus for a laminated core according to Claim 8, wherein the punch has a flat surface at its tip that is orthogonal to the axial direction, each core piece is held in the die with one axial side surface that abuts against the tip of the punch during punching along the tip of the punch, and the next core piece is laminated on the one side surface with the adhesive interposed therebetween. Manufacturing apparatus for a laminated core.

12. A manufacturing apparatus for a laminated core according to Claim 8, comprising a feeding device for sequentially performing application of the adhesive and punching out of the core piece while feeding the steel plate, wherein the adhesive application device includes a plurality of discharge parts arranged in the feeding direction of the steel plate and capable of applying to the same location, and the application amount is set by the number of application times to the same location. Manufacturing apparatus for a laminated core.

13. A manufacturing apparatus for a laminated core according to Claim 8, comprising a feeding device for sequentially performing application of the adhesive and punching out of the core piece while feeding the steel plate. The adhesive application device includes a plurality of discharge parts arranged in the feeding direction of the steel plate and applying the adhesive to different locations of the steel plate. A laminated core manufacturing device.

14. A laminated core manufacturing device according to any one of Claims 8 to 13, wherein the adhesive application device applies the adhesive by an inkjet method. A laminated core manufacturing device.

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