Method for manufacturing a spiral core

Abstract

To provide a method of manufacturing a spiral core that can improve the processing accuracy of a spiral core.SOLUTION: In a method of manufacturing a spiral core 1, band-shaped steel plates 10 are rolled into a circular shape in a plate surface direction S, and are stacked a spiral shape in a plate thickness direction T. Then, an adhesive 2 is applied to the band-shaped steel plates 10 rolled into the circular shape, and the band-shaped steel plates 10 are adhered to each other in a spiral shape with the adhesive 2 by making use of own weights of the band-shaped steel plates 10. Each band-shaped steel plate 10 has an inner peripheral side portion 11 having an approximately constant thickness and an outer peripheral side portion 12 having a gradually reducing thickness toward an outer peripheral side on the outer peripheral side of the inner peripheral side portion 11. The adhesive 2 is applied to the inner peripheral side portion 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a spiral core.

Background Art

[0002] Cylindrical cores such as stator cores are manufactured as laminated cores formed by punching circular steel plates from steel plate materials and laminating them, or as spiral cores formed by spirally laminating strip steel plates while rolling them into a circular shape. Although the spiral core has a drawback such that a tapered surface is formed on the cross section of the strip steel plate, it has an advantage that the yield of the steel plate material is good.

[0003] As an example of a method for manufacturing a spiral core, for example, there is a method for manufacturing a stator core of an electric motor described in Patent Document 1. In the manufacturing method of this Patent Document 1, a step of pressing a strip material in the plate thickness direction and extending it by a predetermined amount in the longitudinal direction, and a step of spirally winding the extended strip material around a winding jig are performed. Then, the winding step is performed while engaging a notch between the comb teeth of the strip material with a convex portion provided on the winding jig, so that no misalignment occurs between the comb teeth of the strip material spirally laminated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the method for manufacturing a spiral core, since a tapered surface is formed on the cross section of the strip steel plate, fixing by fitting or caulking the strip steel plates to each other in a predetermined shape is not used, and it is generally performed to join the strip steel plates by welding. However, when joining the strip steel plates by welding, there is a risk that the accuracy of the diameter of the spiral core or the like may decrease.

[0006] This invention has been made in view of the above problems, and aims to provide a method for manufacturing a helical core that can improve the processing accuracy of the helical core. [Means for solving the problem]

[0007] One aspect of the present invention is, A method for manufacturing a spiral core (1) by rolling a strip of steel sheet (10) in a circular shape in the sheet surface direction (S) and stacking them spirally in the sheet thickness direction (T), An adhesive (2) is applied to the circularly rolled steel strip, and the steel strips are joined together in a spiral shape using the adhesive, utilizing the weight of the steel strips themselves. The aforementioned strip-shaped steel plate has a plurality of notches (13) formed at predetermined intervals along its longitudinal direction, Based on the position of the notch, detected by the position detection device (55) for detecting the position of the notch in the longitudinal direction of the strip-shaped steel plate, the bonding position between the strip-shaped steel plates is detected. stomach , Using a pair of rollers (51) for rolling the strip-shaped steel sheet into a circular shape in the direction of the sheet surface, a winding shaft (52) for winding the circularly rolled strip-shaped steel sheet in a spiral shape, and a coating head (53) for intermittently applying the adhesive to the circularly rolled strip-shaped steel sheet, The timing of intermittently applying the adhesive from the application head to the strip-shaped steel plate is controlled in synchronization with the rotational peripheral speed of the winding shaft. The position detection device detects the load generated on the pair of rollers and uses the change in load when the notch formation position reaches the pair of rollers to detect the notch formation position. This relates to the manufacturing method of the spiral core. [Effects of the Invention]

[0008] In the method for manufacturing a spiral core according to one embodiment described above, an adhesive is applied to a circularly rolled strip of steel, and the strips are joined together in a spiral shape by the adhesive using the weight of the steel strips themselves. With this configuration, the steel strips can be fixed together without the need for crimping or welding. Therefore, when fixing the circularly rolled strips of steel together, almost no stress is generated in the steel strips, and the steel strips are less likely to deform.

[0009] Therefore, according to the method for manufacturing a helical core according to one embodiment described above, the processing accuracy of the helical core can be improved.

[0010] The reference numerals in parentheses for each component shown in one embodiment of the present invention indicate the correspondence with the reference numerals in the figures of the embodiment, but the components are not limited to those described in the embodiment. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is an explanatory diagram showing a manufacturing apparatus for a spiral core according to an embodiment. [Figure 2] Figure 2 is an explanatory diagram showing a spiral core according to an embodiment. [Figure 3] Figure 3 is an explanatory diagram showing a cross-section of a portion of a helical core according to an embodiment. [Figure 4] Figure 4 is an explanatory diagram showing an enlarged cross-section of a portion of the helical core according to the embodiment. [Figure 5] Figure 5 is an explanatory diagram showing the state in which adhesive is applied to a circularly rolled steel strip according to an embodiment. [Modes for carrying out the invention]

[0012] A preferred embodiment of the method for manufacturing the helical core described above will be explained with reference to the drawings. <Embodiment> In the manufacturing method of the helical core 1 of this embodiment, as shown in Figure 1, a strip of steel sheet 10 is rolled in a circular shape in the sheet surface direction S and stacked in a spiral shape in the sheet thickness direction T. Then, adhesive 2 is applied to the circularly rolled strip of steel sheet 10, and the strips of steel sheet 10 are bonded together in a spiral shape by the adhesive 2 using the weight of the strips of steel sheet 10.

[0013] The manufacturing method for the helical core 1 of this embodiment will be described in detail below. (Spiral core 1 and adhesive 2) As shown in FIG. 2, the spiral core 1 of this embodiment constitutes a stator core of a rotating electric machine such as an electric motor or a generator. The spiral core 1 is formed in a cylindrical shape by a strip steel plate 10 laminated in a spiral shape. In the spiral core 1, the strip steel plates 10 adjacent to each other in the stacking direction L, which is the direction of the central axis of the spiral core 1, are adhered to each other via an adhesive 2.

[0014] In the stator core formed by the spiral core 1 of this embodiment, while no slots (recesses) for arranging coils are formed, a plurality of notch portions 13 are formed at predetermined intervals on the outer peripheral side. The notch portions 13 are used for positioning in the circumferential direction of the stator core, detecting the adhesion position, etc. The coil is arranged on the inner peripheral side or the outer peripheral side of the stator core, and a rotor is arranged on the inner peripheral side or the outer peripheral side of the stator core. The stator core formed by the spiral core 1 may have a plurality of slots (recesses) for arranging coils formed on the inner peripheral side or the outer peripheral side. The notch portions 13 may be formed at predetermined intervals on the inner peripheral side of the stator core.

[0015] The adhesive 2 of this embodiment is a curable adhesive (anaerobic adhesive), and its curing is promoted by mixing a curing accelerator 3. In the manufacturing method of the spiral core 1, the adhesive 2 and the curing accelerator 3 are applied to the same part on the surface of the strip steel plate 10 formed in a spiral shape, and thus they are mixed.

[0016] As shown in FIGS. 3 and 4, the strip steel plate 10 in the spiral core 1 of this embodiment is composed of an inner peripheral side portion 11 having a substantially constant thickness on the inner peripheral side of the spiral core 1 and an outer peripheral side portion 12 whose thickness decreases as it goes to the outer peripheral side on the outer peripheral side of the inner peripheral side portion 11. The inner peripheral side portion 11 is formed by a pair of parallel planes 111 whose surfaces on both sides are parallel to each other, and the outer peripheral side portion 12 is formed by a pair of inclined planes 121 whose surfaces on both sides incline so as to approach each other as it goes to the outer peripheral side. In FIG. 3, the portion in the stacking direction D of the spiral core 1 is appropriately omitted and shown.

[0017] The outer peripheral portion 12 is formed by a pair of inclined surfaces 121 because, when the strip-shaped steel plate 10 is bent into a circular shape in the plate surface direction S, the portion located on the outer peripheral side needs to be stretched more. The inner peripheral portion 11 may also be formed by a pair of inclined surfaces 121 such that the thickness decreases slightly towards the portion located on the outer peripheral side in order to bend it into a circular shape in the plate surface direction S.

[0018] The adhesive 2 and curing accelerator 3 are provided on the inner circumferential portion 11 formed by a pair of parallel surfaces 111, and the multiple strip-shaped steel plates 10 constituting the helical core 1 are bonded to each other at the inner circumferential portion 11. As shown in Figure 5, the adhesive 2 and curing accelerator 3 may be provided as dots at predetermined intervals in the circumferential direction C of the helical core 1, or they may be provided linearly along the circumferential direction C of the helical core 1. In addition, the adhesive 2 and curing accelerator 3 may be provided at multiple positions in the radial direction R of the helical core 1.

[0019] (Manufacturing equipment 5) As shown in Figure 1, the manufacturing method for the spiral core 1 uses a manufacturing apparatus 5 for the spiral core 1. The manufacturing apparatus 5 includes a pair of rollers 51 that roll (form) a strip of steel sheet 10 into a circular shape in the sheet surface direction S, a winding shaft 52 that winds the circularly rolled strip of steel sheet 10 into a spiral shape, a first coating head 53 that intermittently applies adhesive 2 to the circularly rolled strip of steel sheet 10, and a second coating head 54 that continuously or intermittently applies a curing accelerator 3 to the circularly rolled strip of steel sheet 10 to promote the curing of the adhesive 2. The pair of rollers 51 are rotationally driven by a rotational drive source 511 and are configured to feed out the strip of steel sheet 10 while forming it. The winding shaft 52 is rotationally driven by a rotational drive source 521.

[0020] The rotational drive source for the winding shaft 52 is configured to rotate the winding shaft 52 in synchronization with the feed speed of the strip steel sheet 10 by the pair of rollers 51 of the feed forming device. The pair of rollers 51 are configured to form the outer peripheral portion 12 of the strip steel sheet 10, and are formed in a tapered shape where the outer diameter increases towards the outer peripheral side of the outer peripheral portion 12.

[0021] As shown in Figure 5, the first coating head 53 is configured to dispense or drip adhesive 2 at predetermined time intervals. The adhesive 2 dispensed or dripped from the first coating head 53 is applied to the upper surface of the inner circumference portion 11 of the strip-shaped steel plate 10. The second coating head 54 is configured to dispense or drip curing accelerator 3 continuously. The adhesive 2 dispensed or dripped from the second coating head 54 is applied to the upper surface of the inner circumference portion 11 of the strip-shaped steel plate 10.

[0022] In this embodiment, the curing accelerator 3 is applied from the second coating head 54 to the upper surface of the inner circumference portion 11 of the strip-shaped steel plate 10, and then the adhesive 2 is applied from the first coating head 53 so as to overlap the curing accelerator 3 applied to this surface. Alternatively, the adhesive 2 may be applied from the first coating head 53 to the upper surface of the inner circumference portion 11 of the strip-shaped steel plate 10, and then the curing accelerator 3 may be applied from the second coating head 54 so as to overlap the adhesive 2 applied to this surface.

[0023] Furthermore, the manufacturing apparatus 5 is equipped with a cutter 56 that cuts the strip steel plate 10 when a strip steel plate 10 of a predetermined length is wound onto the winding shaft 52.

[0024] The manufacturing apparatus 5 used in the manufacturing method of the helical core 1 may be configured to control the timing of intermittently applying the adhesive 2 from the first application head 53 to the strip steel plate 10 in synchronization with the rotational peripheral speed of the winding shaft 52. In this case, the adhesive 2 can be applied to a target position in the circumferential direction C of the helical core 1 being manufactured. Furthermore, for example, when shape-changing portions such as slots or notches 13 are formed at predetermined intervals in the circumferential direction C on the outer or inner circumference side of the helical core 1, the adhesive 2 can be applied while avoiding these shape-changing portions.

[0025] Furthermore, as shown in Figure 1, the manufacturing apparatus 5 may also be equipped with a position detection device 55 for detecting the formation positions of notches 13 formed at predetermined intervals in the strip steel sheet 10 in the longitudinal direction of the strip steel sheet 10. The position detection device 55 is composed of, for example, a photointerrupter that detects the presence or absence of notches 13 by the presence or absence of light transmission. In this case, the first coating head 53 receives a detection signal from the position detection device 55, grasps the formation positions of the notches 13 in the strip steel sheet 10, and is configured to discharge or drip the adhesive 2 while avoiding the notches 13. In this case as well, the winding shaft 52 rotates in synchronization with the rotational speed of the pair of rollers 51. In this case as well, the adhesive 2 can be appropriately applied to the target position while avoiding discharge or dripping of the adhesive 2 onto the notches 13.

[0026] Alternatively, the load generated on the pair of rollers 51 may be made detectable, and the formation position of the notch 13 may be detected by utilizing the change in load when the formation position of the notch 13 reaches the pair of rollers 51. When the formation position of the notch 13 is sandwiched between the pair of rollers 51, the rolling area of ​​the strip steel plate 10 decreases, and the load generated on the pair of rollers 51 decreases.

[0027] (Manufacturing method) In manufacturing the spiral core 1, the strip steel sheet 10 is fed longitudinally from the raw material roll by the rotation of a pair of rollers 51. The outer peripheral portion 12 of the circularly rolled strip steel sheet 10 is then rolled by the pair of rollers 51 so that it forms a pair of inclined surfaces 121 whose thickness decreases towards the outer edge. In the cross section perpendicular to the longitudinal direction of the strip steel sheet 10, an inner peripheral portion 11 and an outer peripheral portion 12 with substantially constant thickness are formed.

[0028] At this time, the winding shaft 52 rotates in sync with the rotation of the pair of rollers 51, and the circularly rolled strip of steel sheet 10 is wound onto the outer circumference of the winding shaft 52. More specifically, the rotational drive source 521 of the winding shaft 52 rotates the winding shaft 52 at a peripheral speed corresponding to the feed rate of the strip of steel sheet 10 by the rotational drive source 511 of the pair of rollers 51, and winds the circularly rolled strip of steel sheet 10 onto the winding shaft 52.

[0029] Furthermore, when the strip steel sheet 10 is wound onto the winding shaft 52, the hardening accelerator 3 is continuously applied from the second coating head 54 to the upper parallel surface 111 that forms the inner circumference portion 11 of the strip steel sheet 10. In addition, the adhesive 2 is intermittently applied from the first coating head 53 to the upper parallel surface 111 that forms the inner circumference portion 11 of the strip steel sheet 10 at a position overlapping with the hardening accelerator 3.

[0030] Then, when the circularly rolled strip steel sheet 10 overlaps the lower strip steel sheet 10 due to its own weight, the adhesive 2 and curing accelerator 3 are sandwiched between the upper and lower strip steel sheets 10. The upper and lower strip steel sheets 10 are then bonded together by the adhesive 2 and curing accelerator 3. After that, when a predetermined length of strip steel sheet 10 is wound onto the winding shaft 52, the strip steel sheet 10 is cut by the cutter 56 to produce the spiral core 1.

[0031] (Effects and Benefits) In the manufacturing method of the spiral core 1 of this embodiment, an adhesive 2 and a hardening accelerator 3 are applied to a circularly rolled strip of steel sheet 10, and the strips of steel sheet 10 are bonded together in a spiral shape using the adhesive 2 and hardening accelerator 3, utilizing the weight of the strips of steel sheet 10. With this configuration, the strips of steel sheet 10 can be firmly fixed together without the need for fixing by crimping or joining by welding. Therefore, when fixing the circularly rolled strips of steel sheet 10 together, almost no stress is generated in the strips of steel sheet 10, and the strips of steel sheet 10 are less likely to deform.

[0032] Therefore, the manufacturing method of the helical core 1 according to this embodiment makes it possible to improve the processing accuracy of the helical core 1.

[0033] In conventional spiral cores, the entire length of the strip-shaped steel plate 10, from the inner end face to the outer end face, is formed by a pair of inclined surfaces 121 whose thickness decreases towards the outer edge. As a result, the adhesive 2 is applied to the inclined surfaces 121 of the strip-shaped steel plate 10, and the inclined surfaces 121 of the strip-shaped steel plate 10 are bonded together by the adhesive 2. However, there was a problem in that the bond between the strip-shaped steel plates 10 could not be made strong enough due to the gaps between them.

[0034] On the other hand, in this embodiment, the parallel surfaces 111 of the inner circumferential portions 11 of the strip-shaped steel plates 10 forming the helical core 1 are bonded together by the adhesive 2 and the curing accelerator 3. As a result, the adhesive 2 can firmly bond the strip-shaped steel plates 10 together in the helical core 1.

[0035] Furthermore, in the manufacturing method of the helical core 1 of this embodiment, the strip steel plates 10 can be laminated together while applying the adhesive 2 and the curing accelerator 3. This reduces the time required to manufacture the helical core 1.

[0036] The present invention is not limited to these embodiments, and further different embodiments can be constructed without departing from the spirit of the invention. Furthermore, the present invention includes various modifications, modifications within the equivalent range, etc. Moreover, various combinations and forms of components conceivable from the present invention are also included in the technical concept of the present invention. [Explanation of Symbols]

[0037] 1. Helical core 10 Strip steel plates 11 Inner part 12 Outer periphery 2. Adhesive 3. Curing accelerator 51 Laura 52 reeling shaft 53, 54 Dispensing head

Claims

1. A method for manufacturing a spiral core (1) by rolling a strip of steel sheet (10) in a circular shape in the sheet surface direction (S) and stacking them spirally in the sheet thickness direction (T), The adhesive (2) is applied to the circularly rolled steel strip, and the steel strips are joined together in a spiral shape using the adhesive, utilizing the weight of the steel strips themselves. The aforementioned strip-shaped steel plate has a plurality of notches (13) formed at predetermined intervals along its longitudinal direction, Based on the position of the notch detected by the position detection device (55) for detecting the position of the notch in the longitudinal direction of the strip-shaped steel plate, the bonding position between the strip-shaped steel plates is detected. Using a pair of rollers (51) for rolling the strip-shaped steel sheet into a circular shape in the direction of the sheet surface, a winding shaft (52) for winding the circularly rolled strip-shaped steel sheet in a spiral shape, and a coating head (53) for intermittently applying the adhesive to the circularly rolled strip-shaped steel sheet, The timing of intermittently applying the adhesive from the application head to the strip-shaped steel plate is controlled in synchronization with the rotational peripheral speed of the winding shaft. A method for manufacturing a spiral core, wherein the position detection device detects the load generated on the pair of rollers and detects the position of the notch by utilizing the change in load when the notch formation position reaches the pair of rollers.

2. The outer peripheral portion (12) of the circularly rolled steel strip is rolled by a pair of rollers so that it becomes an inclined surface (121) in which the thickness decreases towards the outer peripheral side. A method for manufacturing a spiral core according to claim 1, wherein the adhesive is applied from the coating head to the parallel surfaces (111) that form the inner circumferential portion (11) of the strip-shaped steel plate, and the parallel surfaces of the strip-shaped steel plate are bonded together with the adhesive.

3. The method for manufacturing a spiral core according to claim 1 or 2, wherein the coating head comprises a first coating head (53) for intermittently applying the adhesive to the strip-shaped steel plate, and a second coating head (54) for continuously or intermittently applying a curing accelerator (3) to accelerate the curing of the adhesive to the strip-shaped steel plate.

4. The method for manufacturing a spiral core according to claim 3, wherein the first coating head receives a detection signal from the position detection device, determines the position of the notch in the strip-shaped steel plate, and dispenses or drops the adhesive while avoiding the notch.

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