Manufacturing method and manufacturing device for laminated steel sheet

Abstract

A method and an apparatus for manufacturing laminated steel sheets suitable for high-speed manufacturing of laminated steel sheets are provided. [Solution] In a manufacturing method for laminated iron cores, in which iron cores are punched out from an intermittently transported strip-shaped thin steel sheet 10, glued, and stacked in sequence, an adhesive discharge nozzle 24 is provided that sprays adhesive from the underside of an outer shape punch 22 placed in the upper mold, and the punch 22 descends into a die hole formed in a die plate 32 held in the lower mold 30 to punch out the iron core from the strip-shaped thin steel sheet 10, after which the punch rises and moves away from the die hole, and at this point in time when the discharge space surrounded by the underside of the punch 22 and the member containing the punched iron core is connected to the atmosphere, adhesive is sprayed from the adhesive discharge nozzle 24 onto the top surface of the punched iron core.

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for manufacturing laminated steel sheets (laminated iron cores) used in motors and the like. [Background technology]

[0002] A conventional method for producing laminated cores for use in the stators and rotors of rotating electrical machines involves using a progressive die including a punching die (die set) at multiple locations to punch out cores from an intermittently transported strip-shaped thin steel plate, stacking the punched cores sequentially in the die, and bonding them together with an adhesive to obtain a laminated core.

[0003] For example, in Patent Document 1, an adhesive applicator is provided facing the underside of the thin steel plate on the upstream side (forward) before the outer shape is punched out by the punch, and adhesive is dispensed from below upward.

[0004] Furthermore, as shown in FIG. 2D of Patent Document 2, a technique is known in which adhesive is dripped onto a thin steel sheet from the lower end of an adhesive discharge means disposed on an outline punch while a stripper plate is pressing the thin steel sheet against a lower die and the lower surface of the outline punch is spaced apart from the upper surface of the thin steel sheet.

[0005] More specifically, an enclosed space is formed by the stripper plate, the lower die, the previously punched iron core, and the underside of the outline punch, and adhesive is dripped onto the thin steel plate from the lower end of the adhesive discharge means. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-25218 [Patent Document 2] Patent No. 6618203 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the case of Patent Document 1, the ejected adhesive adheres to the underside of the thin steel plate, and in order to prevent the adhesive from adhering to the die surface, a recessed groove is formed in the upper surface of the die corresponding to the outlet of the adhesive application device. However, since the position where the adhesive is applied and the position where the outline is punched are separate, it takes time to feed the thin steel sheet, and it is difficult to eliminate the possibility that the adhesive will adhere to the die surface.

[0008] On the other hand, in the method of Patent Document 2, the adhesive is "dripped" onto the thin steel plate, which takes a long time to "drip" and slows down the processing speed for applying the adhesive onto the thin steel plate, and is therefore considered to be unsuitable for high-speed manufacturing of laminated steel plates.

[0009] Therefore, a main object of the present invention is to provide a method and an apparatus for manufacturing laminated steel sheets that are suitable for manufacturing laminated steel sheets at high speeds. [Means for solving the problem]

[0010] The embodiment that solves the above problem is as follows. (First aspect) In a manufacturing method of laminated cores, cores are punched out from intermittently transported strip-shaped thin steel plates, and then the cores are laminated one after another by bonding the sheets together. An adhesive discharge nozzle is provided to inject adhesive from the underside of the punch for punching the outer shape arranged in the upper die, The punch descends into a die hole formed in a die held by a lower die to punch out an iron core from the strip-shaped thin steel plate, Thereafter, the punch rises and moves away from the die hole, and at the point when the discharge space surrounded by the lower surface of the punch and the die member containing the punched iron core is connected to the atmosphere, adhesive is sprayed from the adhesive discharge nozzle onto the upper surface of the punched iron core.

[0011] (Second aspect) In a laminated core manufacturing device, cores are punched out from intermittently conveyed strip-shaped thin steel plates, and then the cores are bonded and laminated in order. An adhesive discharge nozzle is provided to inject adhesive from the underside of the punch for punching the outer shape arranged in the upper die, a means for punching out an iron core from the strip-shaped thin steel plate by lowering the punch into a die hole formed in a die held by a lower die; an adhesive injection means for injecting adhesive from the adhesive injection nozzle onto the upper surface of the punched iron core when the punch is raised and separated from the die hole and a discharge space surrounded by the lower surface of the punch and the die member including the punched iron core is communicated with the atmosphere; 1. A laminated core manufacturing apparatus comprising: [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a method and an apparatus for manufacturing laminated steel sheets that are suitable for manufacturing laminated steel sheets (laminated iron cores) at high speed. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a schematic diagram of a manufacturing apparatus according to an embodiment in a state before punching an outer shape. [Figure 2] FIG. 10 is a schematic diagram illustrating a state in which the position of the thin steel plate is regulated by the stripper plate. [Figure 3] FIG. [Figure 4] FIG. 10 is a schematic diagram of an adhesive injection state. [Figure 5] FIG. 10 is a schematic diagram of an example of the arrangement of receiving devices. [Figure 6] FIG. 10 is a schematic diagram showing the state in which the punched hand core is held by the receiving device. [Figure 7] FIG. 10 is a schematic diagram of a laminated core being carried out. [Figure 8] FIG. 10 is an explanatory diagram of adhesive discharge and spray timing. [Figure 9] FIG. 2 is an explanatory diagram of the relationship between a punch for punching an outer shape and an iron core. [Figure 10] 10A and 10B are schematic diagrams illustrating examples of accommodation holes for adhesive discharge nozzles. [Figure 11] 10A and 10B are schematic diagrams illustrating an example of vertical movement of the adhesive discharge nozzle. [Figure 12] FIG. 1 is a schematic diagram of an example of outward discharge and spray from an adhesive discharge nozzle. [Figure 13] FIG. 10 is a schematic diagram of an example of carrying out a laminated core. [Figure 14] FIG. 1 is a schematic diagram of an example of an adhesive application site. [Figure 15] 10 is a schematic diagram of an example of an adhesive application area and the underside of a punch for punching an outline. FIG. [Figure 16] 1A is an example of an adhesive application portion, and FIG. 1B is an explanatory diagram showing the relationship between the example of an adhesive application portion and the position of the adhesive discharge nozzle after rotation of the laminated core. [Figure 17] FIG. 10 is a cross-sectional view of an example of an arrangement of an adhesive application device. [Figure 18] FIG. [Figure 19] FIG. [Figure 20] 18 is a schematic diagram of an example of the arrangement of a resin sleeve (an enlarged view of a main part of FIG. 17). DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, embodiments of the present invention will be described in detail below with reference to the drawings.

[0015] (Outline of manufacturing equipment) FIG. 1 shows the main parts of the manufacturing equipment, illustrating the process of punching the core's outer shape from an intermittently conveyed strip-shaped thin steel plate (e.g., silicon steel plate) 10 (FIG. 1 does not show the punched shape of the holes in the core prior to the outer shape punching). It also shows the manufacturing equipment for laminated cores, in which the steel plates are glued and stacked in order, and shows the stages of punching the core's outer shape from the thin steel plate 10 and applying adhesive at the same position. In the embodiment, punching out the outer shape of the iron core and applying the adhesive are carried out at the same position (process), so unlike Patent Document 1, there is no need for intermittent transport from the adhesive application station to the iron core outer shape punching station, making it possible to manufacture at high speed.

[0016] In the manufacturing apparatus of the embodiment, an adhesive discharge nozzle 24 is provided in an outer shape punch 22 arranged on an upper mold 20 that moves up and down, and the adhesive discharge nozzle 24 faces an opening on the lower surface 22a of the outer shape punch 22. With the adhesive discharge nozzle 24 facing the opening on the lower surface 22a of the punch 22 for punching the outer shape, the punch 22 descends into the die hole 32a of the die plate 32 held by the fixed lower mold 30 to punch out the outer shape of the iron core from the strip-shaped thin steel plate 10.

[0017] A stripper plate 26 is provided below the upper die 20. When a strip-shaped thin steel sheet 10 is transported, before the punch 22 punches out the thin steel sheet 10, the stripper plate 26 is lowered by a biasing member 27 such as a spring to press the thin steel sheet 10 against the die plate 32 and regulate the vertical position of the thin steel sheet 10.

[0018] The adhesive discharge nozzle 24 is provided such that, for example, its lower end is located above the lower surface of the outline punching punch 22, and the lower end of the adhesive discharge nozzle 24 faces the opening in the lower surface of the outline punching punch 22. In the illustrated state, the adhesive discharge nozzle 24 itself is provided, for example, to penetrate the outline punching punch 22 from top to bottom, but the arrangement of the adhesive discharge nozzle 24 and the flow path of the adhesive can be selected as appropriate.

[0019] The embodiment includes an adhesive application device 25, which is composed of an adhesive supply mechanism having a syringe or the like for storing adhesive, an adhesive discharge nozzle 24 provided in the punch 22, and an adhesive injection mechanism including an opening / closing valve for injecting adhesive. The adhesive discharge nozzle 24 in this embodiment sprays the adhesive liquid downward without contacting the upper surface of the thin steel plate 10. As the adhesive discharge nozzle 24, for example, a known jet type dispenser can be selected. The adhesive discharge nozzles 24 are arranged, for example, on a circle around the vertical axis of the punch 22, and the number of nozzles to be installed is selected to be one, two or more depending on the number of bonding locations required.

[0020] The adhesive spraying mechanism for spraying the adhesive includes, for example, a piezoelectric valve actuator, and the timing of starting and stopping the spraying is determined based on a command signal from the control device 50, and the adhesive is pressurized and sprayed, for example, as fine droplets.

[0021] Next, an example of the manufacturing process will be described with reference to FIGS. As shown in FIG. 1, when a strip-shaped thin steel sheet 10 is transported to the punching station, it is placed above the upper surface of a die plate 32 by a lifter 33 (the die is not shown).

[0022] Next, as shown in FIG. 2, before the punch 22 punches out the thin steel sheet 10, the stripper plate 26 descends to press the thin steel sheet 10 against the die plate 32, thereby restricting the vertical position of the thin steel sheet 10. In this state, the lower surface of the punch 22 is spaced apart from the upper surface of the thin steel sheet 10, and an enclosed space is formed between the side surface of the through hole of the stripper plate 26 and the thin steel sheet 10. This enclosed space is indicated by the symbol CS. In this embodiment, the tip of the adhesive discharge nozzle 24 is disposed above the lower surface of the punch 22 and faces the sealed space CS.

[0023] Thereafter, as shown in FIG. 3, with the adhesive discharge nozzle 24 facing the opening on the underside of the punch 22 for punching the outer shape, the punch 22 is lowered into the die hole 32a formed in the die plate 32 held by the lower die 30, and the outer shape of the iron core is punched out of the thin steel plate 10.

[0024] Next, as shown in FIG. 4, punch 22 rises and moves away from die hole 32a, upper mold 20 rises, and stripper plate 26 also rises. As a result, the discharge space surrounded by the underside of punch 22 and the member including the punched iron core communicates with the atmosphere, that is, when a communication space HS is formed, adhesive is sprayed downward from adhesive discharge nozzle 24 passing through the inside of punch 22 and onto the top surface of the punched iron core.

[0025] Thereafter, the punched core is rotated by a predetermined angle (for example, 90°) as shown in Fig. 5, and at the same time, the thin steel sheet 10 is transported downstream. The next outline punching is performed at the outline punching station as shown in Fig. 6, and then adhesive injection as shown in Fig. 4 is performed.

[0026] When punching the outer shape of Figure 6, the bottom surface of the punch is a flat surface without adhesive discharge nozzles 24, so it can crush the adhesive between the previously applied iron cores. This spreads the adhesive evenly and stabilizes the adhesive strength.

[0027] The process shown in FIGS. 1 to 5 is regarded as one unit, and a predetermined number of iron cores are subjected to punching and adhesive application.

[0028] The punched cores can be received by a receiving device 40 shown in Fig. 7, for example, and stacked in order. The receiving device 40 has a back pressure plate portion 40a at its top and a holding portion 40b that elastically holds the back pressure plate portion 40a. The receiving device 40 is preferably rotatable around a vertical axis and can be retracted below the lower die 30 so that a predetermined number of laminated cores M (see Fig. 7) can be discharged to the destination.

[0029] That is, the die 32A and squeeze ring 41 support the punched core as shown in FIG. 6, and then support the next punched core while rotated by a predetermined angle around the vertical axis as shown in FIG. The iron cores are received and rotated one by one in order, and the receiving device 40 holds the laminated iron cores in a stacked state. When the predetermined number of sheets have been stacked, as shown in FIG. 7, the receiving device 40 retreats below the lower mold 30 and discharges the predetermined number of stacked laminated cores M (see FIG. 7) to the destination.

[0030] As described above, for example, in Patent Document 1, an adhesive applicator is provided facing the underside of the thin steel sheet on the upstream side (forward) prior to punching the outer shape with a punch, and in a configuration in which adhesive is dispensed from below upward, there is a risk that the dispensed adhesive will adhere to the underside of the thin steel sheet and then to the die or die plate surface. Furthermore, when a lifter is provided, there is a risk that the adhesive will adhere to the lifter and become impossible to remove, necessitating cleaning.

[0031] In contrast to this, as shown in the embodiment, the punch 22 for punching the outer shape descends to punch out the iron core from the strip-shaped thin steel plate, and adhesive is sprayed onto the top surface of the punched iron core at the same position as this punching, thereby preventing the adhesive from adhering to the die or die plate surface, lifter, etc. Furthermore, the flat, nozzle-free surface on the underside 22a of the punch 22 for punching the outer shape presses (applies pressure to) the punched core onto the previously punched and rotated core, spreading the adhesive that was previously applied onto the punched core and forming a wide bonding surface area, which also brings about the advantage of increasing the adhesive strength.

[0032] In this embodiment, the adhesive is sprayed onto the top surface of the punched iron core, rather than being "dripped" as in Patent Document 2. The embodiment of Patent Document 2 requires a certain amount of time for the "dripping" to be completed, making it unsuitable for high-speed application of adhesive.

[0033] In addition, in the embodiment of Patent Document 2, adhesive is dripped onto the thin steel sheet from the lower end of the adhesive discharge means in a state where the stripper plate presses the thin steel sheet against the lower die and the lower surface of the outline punch is separated from the upper surface of the thin steel sheet, i.e., in a state where an enclosed space is formed between these. The reason for this is not clear, but it is thought that it is because, when "dripping" the adhesive, there is a demand to apply the adhesive as directly downward as possible to avoid the influence of ventilation in the factory. According to an embodiment of the present invention, there is a possibility that processing oil that has been applied in advance to prevent wear on the mold may adhere to the surface of the iron core. However, even if processing oil does adhere to the surface of the iron core, there is an advantage that the processing oil can be pushed aside by spraying and adhesive can be applied.

[0034] According to the embodiment, when punch 22 rises and moves away from die hole 32a, and the discharge space surrounded by lower surface 22a of punch 22 and the member including the punched iron core becomes connected to the atmosphere, that is, when a communication space HS is formed as shown in FIG. 4, adhesive is sprayed from adhesive discharge nozzle 24 onto the upper surface of the punched iron core. Since the adhesive is sprayed at the point when the communicating space HS shown in FIG. 4 is formed from the sealed space CS shown in FIG. 2, the spray direction of the adhesive is uniformly determined and stable.

[0035] For example, as shown in FIG. 4, the point in time before the top dead center of the punch 22 when it is connected to the atmosphere can be linked to a press angle signal, and adhesive can be sprayed from the adhesive discharge nozzle 24 onto the top surface of the punched iron core based on the press angle signal. That is, for example, in a press machine having the relationship between crank angle and ram stroke shown in Figure 8, when the material transfer has finished, the material is pressed down by the stripper plate 26 and punched out until it reaches the bottom dead center of the press, and then the stripper plate 26 rises to form a communicating space HS, at which point adhesive is quickly injected. Then, the material transfer begins. By linking it with the press angle signal, the timing can be controlled accurately and reliably. Furthermore, since the number of punches can be detected, it is possible to determine whether or not adhesive needs to be sprayed on a laminated core basis.

[0036] For example, as shown in Figure 9, a configuration is provided in which the adhesive discharge nozzle 24 is provided such that its lower end is positioned above the lower surface 22a of the punch 22 for punching the outer shape, and the lower end of the adhesive discharge nozzle 24 faces the opening of the lower surface 22a of the punch 22 for punching the outer shape. On the other hand, in Japanese Patent No. 7138899, as shown in Figure 18, the adhesive discharge nozzle is provided to protrude downward from the bottom surface of the punch used for punching the outer shape. In this configuration, the bottom end of the adhesive discharge nozzle may come into contact with the iron core material, causing a dent and possibly damaging the adhesive discharge nozzle. According to the embodiment in which the lower end of the adhesive discharge nozzle 24 is provided facing the opening in the lower surface 22a of the punch 22 for punching the outer shape, the above-mentioned danger can be avoided.

[0037] For example, as shown in FIG. 10, a configuration is provided in which the lower end of a housing hole 22b of a punch 22 provided with an adhesive discharge nozzle 24 has an enlarged surface 22c that enlarges toward a lower surface 22a of the punch 22. This configuration is highly effective in preventing adhesion to the opening of the punch 22 for punching the outer shape.

[0038] 11, the adhesive discharge nozzle 24 may be provided so that its vertical position can be adjusted relative to the punch 22. For example, the vertical movement distance is indicated by the symbol S. After a certain number of shots, the punch and die will need to be polished, but by adjusting the distance between the adhesive discharge nozzle 24 and the target surface, the adhesive can be sprayed in an appropriate state.

[0039] Furthermore, as shown in FIG. 12, for example, a configuration is also provided in which the adhesive is jetted from the adhesive discharge nozzle 24 in the direction toward the outer periphery of the laminated core. In order to maintain the strength of the punch 22, the adhesive discharge nozzle 24 is arranged a predetermined distance inward from the outer periphery of the punch, and although it is difficult to apply adhesive to the outer peripheral edge of the iron core, this problem can be solved.

[0040] As explained above with reference to FIG. 7, the punched cores can be received by, for example, a receiving device 40 shown in FIG. 7 and stacked one after another. During this receiving and stacking process, it is desirable that the thin cores 10a be flat and not warped. If they are warped and not flat, when the adhesive applied to the top surface of the first punched core is pressed by punch 22 to punch the next core, the adhesive will not be able to spread (spread) sufficiently around the periphery, or will flow in an unintended direction, making it difficult to obtain the required adhesive strength between the cores.

[0041] Therefore, it is desirable that the receiving device 40, also shown in Figure 13, has a holding portion 40b that elastically holds the upper back pressure plate portion 40a, and that the laminated core be pressed between the punch 22 and the back pressure plate portion 40. It is also desirable to provide a squeeze ring 41 that is continuous with the die hole 32a of the die plate 32, and to press the outer periphery of the laminated core toward the center. One way to press the outer periphery of the laminated core toward the center is to make the inner diameter of the squeeze ring 41 approximately the same as or smaller than the outer diameter of the punched core. Another example of a configuration for pressing the outer periphery of the laminated core toward the center is to divide the squeeze ring 41 circumferentially and provide a biasing means (such as a spring or movable means) 41a that biases each divided squeeze ring 41 toward the center.

[0042] In this case, it is more desirable that the back pressure by the back pressure plate portion 40a and / or the lateral pressure (biasing force toward the center) of the squeeze ring 41 be adjustable.

[0043] In this embodiment, adhesive is applied by squirting onto the upper surface of the punched iron core 10a at a distance from the adhesive discharge nozzle 24. Therefore, when the adhesive applied to the top surface of the previously punched iron core is pressed by punch 22 to punch the subsequent iron core, it is desirable to press it on the flat surface of the punch that does not have a nozzle opening so that the adhesive can be sufficiently spread (expanded) around the periphery.

[0044] However, even if punch 22 is pressed directly against the upper surface of laminated core 10a, as shown in Figure 14, the position of core 10a facing adhesive discharge nozzle 24 has accommodating hole 22b or enlarged surface 22c open, and the flat surface of lower surface 22a of punch 22 is not in contact with the upper surface of core 10a. Furthermore, the embodiment does not discharge adhesive from an adhesive discharge nozzle that is provided so as to protrude downward from the bottom surface of the punch for punching the outer shape, as in Japanese Patent No. 7138899.

[0045] Therefore, when the adhesive applied to the top surface of the previously punched iron core is pressed by the punch 22 to punch out the subsequent iron core, it is desirable that the die 32A and squeeze ring 41, etc. rotate as shown in Figure 15 so that the adhesive applied to the top surface of the previously punched iron core is not positioned below the adhesive discharge nozzle 24, and that the flat surface on the bottom of the punch 22 abuts against the application area of ​​the previously applied adhesive on the iron core, allowing the adhesive to be sufficiently spread (expanded) around. The rotation of the die 32A and squeeze ring 41 is timed to occur after the punch has left the die in order to avoid interference.

[0046] As an example of such a technique, it is desirable to use a rotary stacking mechanism of an appropriate configuration known to those skilled in the art, which rotates the laminated iron core M around its axis using a die 32A and a squeeze ring 41, as shown in Figure 5, and then, as shown in Figure 15, to abut the flat surface of the lower surface 22a of the punch 22 against the area of ​​the iron core 10a where the adhesive was previously applied, thereby sufficiently spreading (expanding) the adhesive around it.

[0047] As a specific example, as shown in Figure 16(A), when adhesive Ad is applied to an iron core 10a using five adhesive discharge nozzles 24 arranged at an opening angle of 72 degrees from the center of the punch 22, if the laminated iron core M is rotated, for example, 180 degrees around its axis by the receiving device 40 using a rotational stacking mechanism, as shown in Figure 16(B), the application portion of the previously applied adhesive Ad will be positioned opposite the flat surface of the underside 22a of the punch 22 that does not have the adhesive discharge nozzles 24.As a result, the underside 22a of the punch 22 will abut against the application portion of the previously applied adhesive Ad on the iron core 10a, allowing the adhesive to be sufficiently spread (expanded) around.

[0048] In this way, it is desirable to have a rotation process in which adhesive is sprayed from an adhesive discharge nozzle onto the top surface of the punched iron core, and then the laminated iron core is rotated a predetermined angle around the axis by a rotary stacking mechanism, and after the laminated iron core is rotated around the axis by the rotation process, the lower surface of the punch applies pressure to the thin steel plate of the laminated iron core during the next outer shape punching.

[0049] By rotating the laminated core around the axis during the rotation process, the advantage is realized that the adhesive can be sufficiently spread (expanded) around the periphery, provided that, in a plan view of the core, at least one of the multiple adhesive injection positions on the top surface of the previously punched-out iron core and the multiple pressure positions on the top surface of the iron core during the next outer shape punching are in a different relationship.

[0050] In the above embodiment, prior to the step of discharging the adhesive from above to below the thin steel plate 10, a step of applying the adhesive from below to above the thin steel plate 10 may be performed, as has been commonly done in the past. This application of the adhesive from below to above the thin steel plate 10 may be performed by spraying the adhesive, in addition to applying the adhesive by coating.

[0051] Furthermore, in this embodiment, the adhesive discharge nozzle 24 is disposed inside the punch 22 for punching the outer shape, but it may also be a short nozzle disposed between the adhesive applicator 25 of the upper die 20 and the punch 22 for punching the outer shape, or just before the punch 22 for punching the outer shape. In this case, the adhesive becomes droplets and passes through the accommodation hole (through hole) of the punch to be sprayed from the underside of the punch. Also, as shown in Figure 17, the adhesive discharge nozzle 24 is provided inside the adhesive applicator 25, and an adhesive passage that passes through the punch 22 is formed by a resin sleeve 24S. Furthermore, when applying adhesive from the bottom to the top of the thin steel plate 10, if there is at least one difference between the application area of ​​the adhesive and the application area of ​​the adhesive from the adhesive discharge nozzle from the top to the bottom of the thin steel plate 10 in plain view, the advantage of being able to spread (expand) the adhesive sufficiently around the periphery is realized. In this embodiment, it is not essential to rotate the laminated core M by a predetermined angle around the axis by the rotary lamination mechanism. In the embodiment (FIG. 1, etc.), the punch 22 for punching the outer shape projects downward from the inside of the upper die 20, but it may also project downward from the lower surface of the upper die. A clearance may be provided between the accommodation hole of the punch and the nozzle. The adhesive discharge nozzle 24 is long and passes through the receiving hole in the punch 22 for punching the outer shape, but the length is free and may be short.

[0052] Specifically, the adhesive applying device 25 can be arranged on the upper mold 20 in the form shown in FIG. The upper die 20 holds an adhesive applicator 25 and also holds a punch 22 for punching the outer shape by using a punch fixing member 21 . The adhesive applicator 25 has a discharge nozzle 24 and sprays adhesive. The sprayed adhesive passes through a resin sleeve 24S that penetrates the punch 22 for punching the outer shape and an opening on the bottom surface of the punch, and lands on the top surface of the punched iron core held in the lower die 30. The adhesive applicator 25, discharge nozzle 24, resin sleeve 24S, and punch 22 are arranged so that they can rise and fall together with the upper die 20.

[0053] Since vibrations and impacts act on the upper die 20 and the punch 22 for punching the outer shape during the pressing operation, the adhesive applicator 25 housed in the upper die 20 is also subjected to vibrations and impacts. Therefore, it is desirable that the adhesive applicator 25 be provided within the space of the upper mold 20 via elastic shock absorbing members 60, 60 above and below the adhesive applicator 25.

[0054] 17, an adhesive applicator 25 is placed in a recess 20a formed in the upper mold 20, with a lower impact absorbing member 60 interposed between its lower surface and the lower surface of the recess 20a, and an upper impact absorbing member 60 interposed between its upper surface and a fixing member 20b covering the recess 20a, with the adhesive applicator 25 placed in this order. A plan view of the absorbing member 60 is shown in FIG.

[0055] The lower impact absorbing member 60 has flow holes 60a formed at positions corresponding to the resin sleeves 24S of the adhesive discharge nozzles 24 to enable fluid connection with the adhesive application device 25 that supplies adhesive into the resin sleeves 24S of the adhesive discharge nozzles 24.

[0056] The material of the shock absorbing member 60 is preferably an elastic material for absorbing vibrations and / or shocks, and is particularly preferably a rubber material with a Shore A hardness of 25 to 50. The Shore A hardness can be measured in an environment of 23°C in accordance with the description of JIS K6253-3:2012. The shock absorbing member 60 can be fixed to the upper mold 20 or the adhesive applicator 25 by appropriate means.

[0057] As described above, the adhesive application device 25 is subjected to vibrations and shocks, and the vibrations and shocks can be absorbed by the upper shock absorbing member 60 and the lower shock absorbing member 60 . In this embodiment, since the adhesive applicator 25 has a cylindrical shape, it is possible to fix the position restricting member 70 to the upper mold 20 by using fixing members such as fixing bolts 70c in the positioning holes 70b or positioning pins 70d in the positioning holes 70b around the position restricting member 70. A plan view of the position restricting member 70 is shown in FIG.

[0058] The adhesive application device 25 is divided into two parts, an upper part and an lower part, and is fixed to the upper mold 20 by sandwiching a position regulating member 70. This position regulating member 70 can be formed with a wiring relief hole 70e, a weight reduction hole 70f, and the like.

[0059] The type of adhesive is not necessarily limited, but in order to quickly fix the thin steel sheets in a stacked state, it is desirable that the adhesive be an anaerobic adhesive. However, once anaerobic adhesive adheres to metal, it hardens in a short time. If the anaerobic adhesive sprayed from the adhesive discharge nozzle 24 of the adhesive applicator 25 adheres to the metal inner peripheral surface of the communicating hole of the punch 22, the anaerobic adhesive may harden and become impossible to remove.

[0060] Therefore, it is desirable that the metal inner peripheral surface of the punch 22 includes a resin sleeve 24S. It is particularly preferable that the resin sleeve 24S be made of an antistatic material. When the adhesive is sprayed into the resin sleeve 24S and passes through, it is possible to prevent the landing position from shifting due to static electricity.

[0061] As a specific example, the resin sleeve 24S may be made of MC nylon (monomer cast nylon). MC nylon is a type of polyamide (PA) resin known as an engineering plastic (ENPLA), which has improved nylon properties achieved by polymerizing and molding the main raw material, nylon monomer, under atmospheric pressure. This polymerization and molding method is called the cast method, and nylon made by this method has different properties from regular injection-molded or extrusion-molded products, so nylon made by this method is distinguished by the name MC nylon, or monomer-cast nylon.

[0062] A representative example of the resin sleeve 24S having an antistatic function is MC nylon "MC501CDR6-antistatic grade" manufactured by Mitsubishi Chemical Advanced Materials Corporation. This is because the electrical resistance (volume resistivity) is 10 8 ~1010 It is a material that is difficult to charge with static electricity, with a resistance of Ω·cm or less. [Explanation of symbols]

[0063] 10...Thin steel plate 10a...iron core 20…Upper mold 22...Outer shape punch 24...Adhesive discharge nozzle 24S...Resin sleeve 25...Adhesive application device 26...Stripper plate 30…Lower mold 32...Die plate 32A...Die 32a...Die hole 40...Receiving device 40a...Back pressure plate section 40b...Holding part 40b 41...Squeeze ring 50...Control device 60...Shock absorbing member 70...Regulatory components CS…Closed space HS...Communication space

Claims

1. In a manufacturing method of laminated cores, cores are punched out from intermittently transported strip-shaped thin steel plates, and then the cores are laminated one after another by bonding the sheets together. An adhesive discharge nozzle is provided to inject adhesive from the underside of the punch for punching the outer shape arranged in the upper die, It has a rotary lamination mechanism that rotates the laminated core around its axis, an iron core punching step in which the punch is lowered into a die hole formed in a die held by a lower die to punch an iron core out of the strip-shaped thin steel plate; thereafter, the punch is raised and separated from the die hole, and an adhesive injection process is performed in which adhesive is injected from the adhesive injection nozzle onto an upper surface of the punched iron core at a point in time when an ejection space surrounded by a lower surface of the punch and a die member including the punched iron core is communicated with the atmosphere; a rotating step of rotating the laminated core by a predetermined angle around an axis by the rotary lamination mechanism; and a pressing step of pressing the laminated core against the thin steel plate by the lower surface of the punch during the next outer shape punching step after rotating the laminated core around the axis in the rotating step, By rotating the laminated core around the axis in the rotating step, at least one of a plurality of adhesive injection positions on the top surface of the previously punched iron core and a plurality of pressure application positions on the top surface of the iron core during the next outline punching is in a different relationship in a plan view of the iron core. A method for manufacturing a laminated core.

2. a stripper plate provided in the upper die, which restricts vertical movement of the thin steel plate at a lowermost position when the punch is used to punch out the strip-shaped thin steel plate, the discharge space is configured to include the lower surface of the punch, the punched iron core, and the stripper plate, the discharge space is configured to communicate with the atmosphere when the stripper plate separates from the thin steel sheet, When the discharge space is in communication with the atmosphere, adhesive is sprayed from the adhesive discharge nozzle onto the upper surface of the punched iron core. A method for manufacturing a laminated core according to claim 1.

3. 3. A method for manufacturing a laminated core according to claim 1, wherein the time point at which the core is communicated with the atmosphere is linked to a press angle signal, and adhesive is sprayed from the adhesive discharge nozzle onto the upper surface of the punched core based on the press angle signal.

4. 2. A method for manufacturing a laminated core as described in claim 1, wherein the adhesive discharge nozzle has a lower end positioned above the lower surface of the punch for punching the outer shape, and the lower end of the adhesive discharge nozzle is arranged facing an opening on the lower surface of the punch for punching the outer shape.

5. 2. The method for manufacturing a laminated core according to claim 1, wherein a lower end of the accommodation hole of the punch, in which the adhesive discharge nozzle is provided, has an enlarged surface that expands toward the lower surface of the punch.

6. 2. The method for manufacturing a laminated core according to claim 1, wherein the adhesive discharge nozzle is provided so that its vertical position can be adjusted relative to the punch.

7. 2. The method for manufacturing a laminated core according to claim 1, wherein the adhesive is ejected from the adhesive ejection nozzle in a direction toward the outer periphery of the laminated core.

8. 2. The method for manufacturing a laminated core according to claim 1, wherein the laminated core is pressed between the punch and a back pressure plate, and is laterally pressed by a squeeze ring.

9. 9. The method for manufacturing a laminated core according to claim 8, wherein the back pressure of the back pressure plate and the lateral pressure of the squeeze ring are adjustable.

10. In a laminated core manufacturing device, cores are punched out from intermittently conveyed strip-shaped thin steel plates, and then the cores are bonded and laminated in order. An adhesive discharge nozzle is provided to inject adhesive from the underside of the punch for punching the outer shape arranged in the upper die, a means for punching out an iron core from the strip-shaped thin steel plate by lowering the punch into a die hole formed in a die held by a lower die; an adhesive injection means for injecting adhesive from the adhesive discharge nozzle onto the upper surface of the punched iron core when the punch is raised and separated from the die hole and a discharge space surrounded by the lower surface of the punch and the die member including the punched iron core is communicated with the atmosphere, the punch for punching the outer shape and an adhesive application device having an adhesive discharge nozzle for injecting adhesive from the underside of the punch for punching the outer shape are each disposed so as to be raised and lowered integrally with the upper die, the adhesive application device is provided in the space of the upper mold via elastic shock absorbing members above and below the adhesive application device; A laminated core manufacturing apparatus characterized by:

11. A laminated core manufacturing apparatus for punching, bonding, and sequentially laminating iron cores from intermittently conveyed strip-shaped thin steel plates, comprising: An adhesive discharge nozzle is provided to inject adhesive from the underside of the punch for punching the outer shape arranged in the upper die, a means for punching out an iron core from the strip-shaped thin steel plate by lowering the punch into a die hole formed in a die held by a lower die; an adhesive injection means for injecting adhesive from the adhesive discharge nozzle onto the upper surface of the punched iron core when the punch is raised and separated from the die hole and a discharge space surrounded by the lower surface of the punch and the die member including the punched iron core is communicated with the atmosphere, The adhesive dispensing nozzle is configured to include a resin sleeve containing an antistatic material. A laminated core manufacturing apparatus characterized by:

12. the punch for punching the outer shape and an adhesive application device having an adhesive discharge nozzle for injecting adhesive from a lower surface of the punch for punching the outer shape are each disposed so as to rise and fall integrally with the upper die, 12. The laminated core manufacturing apparatus according to claim 10, wherein the adhesive applicator provided in the space of the upper die is fixed to the upper die within the space of the upper die by a position regulating member.

13. 11. The laminated core manufacturing apparatus according to claim 10, wherein the adhesive applicator provided in the space of the upper die has an upper shock absorbing member on its upper surface and a lower shock absorbing member on its lower surface.

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