Stationary induction device

Abstract

To provide a stationary induction device having a wound core with reduced iron loss compared to conventional devices.SOLUTION: A stationary induction device has a wounded core configured from electromagnetic steel sheets. The laminated core includes a lap part where one end and the other end of an electromagnetic steel sheet are lap-joined, a bottom part that is a part opposing the lap part, a first arm part extending from one end of the bottom part to the lap part, and a second arm part extending from the other end of the bottom part to the lap part. The bottom part, the first arm part, and the second arm part each have a main surface part formed by a plane horizontal in the circumferential direction, which is a winding direction of the wound core. Grooves for subdividing magnetic domains are formed on the main surface part.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a stationary induction machine. [Background technology]

[0002] Conventionally, there is a technique for subdividing magnetic domains in an iron core material when forming a wound core. Subdividing magnetic domains is a technique for reducing iron loss by processing an iron core material to disrupt the balance of magnetic energy that forms magnetic domains. For example, Patent Document 1 describes such a technique. Patent Document 1 states that "The wound iron core 10 of the present invention is formed by individually bending grain-oriented electromagnetic steel sheets 40, on whose surfaces strains 20 for controlling magnetic domains extending in the width direction intersecting with the rolling direction are imparted, and assembling them into a wound shape. In the area that becomes the bent portion R1 in the bending process and in the area nearby, grooves 25 extending in the width direction are formed on the surface of the grain-oriented electromagnetic steel sheets 40." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-163942 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above Patent Document 1, grooves are formed at a predetermined interval in the bent portion of the grain-oriented electrical steel sheet and in the region near the bent portion in a direction intersecting the rolling direction of the grain-oriented electrical steel sheet, but the formation of grooves in the bent portion may deteriorate the iron loss characteristics. Also, in the wrap portion of the wound core, the flow of magnetic flux is disturbed, causing magnetic flux crossover, which is likely to cause magnetic flux leakage, causing an increase in iron loss. In order to obtain a wound core with stable low iron loss, it is preferable not to form grooves in the wrap portion.

[0005] An object of the present invention is to provide a stationary induction machine having a wound core with less iron loss than in the past. [Means for solving the problem]

[0006] A stationary induction device according to one embodiment of the present invention is a stationary induction device having a wound core made of electromagnetic steel sheets, the wound core being composed of a lap portion where one end and the other end of the electromagnetic steel sheets are lap-joined, a bottom portion which is a portion facing the lap portion, a first arm portion extending from one end of the bottom portion to the lap portion, and a second arm portion extending from the other end of the bottom portion to the lap portion, the bottom portion, the first arm portion and the second arm portion each having a main surface portion formed by a plane which is horizontal in the circumferential direction which is the winding direction of the wound core, and grooves for subdividing magnetic domains are formed in the main surface portions. Effect of the Invention

[0007] According to one aspect of the present invention, it is possible to provide a stationary induction machine having a wound core with less iron loss than in the past. Other objects, configurations, and effects than those described above will become apparent from the following description of the preferred embodiment of the present invention. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing an example of an iron core manufacturing apparatus for manufacturing a wound iron core in the present embodiment. [Diagram 2] 2 is a diagram showing an example of a schematic internal structure of the roller device shown in FIG. 1. [Diagram 3] FIG. [Figure 4] FIG. 2 is a perspective view of a wound core (with grooves on the main surface of the outer side surface and no grooves on the bent portion). [Diagram 5] FIG. 13 is a diagram for explaining the formation of a groove. [Figure 6] FIG. 13 is a diagram for explaining the formation of a groove. [Figure 7] This is an oblique view of a wound core (there are grooves on the main surface of the outer side and shallow grooves on the bent parts). [Figure 8]This is an oblique view of a wound core (there are grooves on the main surface of the outer side and shallow grooves on the bent parts). [Figure 9] FIG. 1 is an oblique view of a wound core (with grooves on the main surface of the inner side surface and no grooves on the bent portion). [Figure 10] FIG. 1 is an oblique view of a wound core (with grooves on the main surface of the inner side and grooves on the lap portion). [Figure 11] FIG. 2 is a perspective view of a wound core (grooves are present on the main surface of the outer side surface other than the wrap portion, and no grooves are present on the bent portion). [Figure 12] FIG. 1 is an oblique view of a wound core (there are grooves on the main surface of the outer side surface other than the wrap portion, and there are shallow grooves in the bent portion). [Figure 13] FIG. 1 is an oblique view of a wound core (there are grooves on the main surface of the outer side surface other than the wrap portion, and there are shallow grooves in the bent portion). [Figure 14] FIG. 1 is a perspective view of a wound core (grooves are present on the main surface of the inner side surface other than the wrap portion, and no grooves are present on the bent portion). [Figure 15] FIG. 1 is a perspective view of a wound core (grooves are present on the main surface of the outer side surface other than the wrap portion, and grooves are present in the bent portion). [Figure 16] FIG. 1 is a perspective view of a wound core (grooves are present on the main surface of the outer side surface other than the wrap portion, and grooves are present in the bent portion). [Figure 17] FIG. 1 is an oblique view of a wound core (there are grooves on the main surface of the inner side surface other than the wrap portion, and there are shallow grooves on the inner side surface of the bent portion). [Figure 18] FIG. 1 is an oblique view of a wound core (there are grooves on the main surface of the inner side surface other than the wrap portion, and there are shallow grooves in the bent portion). [Figure 19] This is an oblique view of a wound core (there is a groove on the main surface of the inner side and a shallow groove on the bent portion). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The examples are illustrative for explaining the present invention, and are omitted and simplified as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise limited, each component may be singular or plural. The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] Fig. 1 is a diagram showing an example of an iron core manufacturing apparatus for manufacturing a wound iron core in this embodiment. As shown in Fig. 1, the iron core manufacturing apparatus 1000 has a material feed uncoiler 100 that pays out electromagnetic steel sheets 500 (e.g., amorphous thin magnetic material) that are stacked and wound into a hoop shape, a roller device 200 that subdivides the magnetic domains of the electromagnetic steel sheets 500 paid out from the material feed uncoiler 100 and conveys the magnetic steel sheets 500 with the subdivided magnetic domains to a material winding uncoiler 300, a material winding uncoiler 300 that winds up the magnetic steel sheets 500 with the subdivided magnetic domains conveyed from the roller device 200, and a control device 400 that controls the operation of the iron core manufacturing apparatus 1000 including the material feed uncoiler 100, the roller device 200, and the material winding uncoiler 300. The control device 400 may be configured as a general computer having a processor 410 and a memory 420 as hardware.

[0011] Fig. 2 is a diagram showing an example of a schematic internal structure of the roller device 200 shown in Fig. 1. As shown in Fig. 2, the roller device 200 has a leveller 201 that straightens out the curl of the electromagnetic steel sheet 500 fed from the material feed uncoiler 100, a pressure roller 202 that presses the electromagnetic steel sheet 500 whose curl has been straightened by the leveller 201 in the direction of the groove roller 203, and a groove roller 203 that forms grooves in the electromagnetic steel sheet 500 to subdivide magnetic domains. The pressure roller 202 and the groove roller 203 form a groove forming portion 204.

[0012] FIG. 3 is an enlarged view of the groove forming section. In FIG. 3, the groove forming section 204 is shown as a view seen from the downstream side to the upstream side in the rolling direction of the electromagnetic steel sheet 500. As shown in FIG. 3, in the groove forming section 204, the roller shaft 301 of the pressure roller 202 is raised toward the groove roller 203 side to press the pressure roller 202 against the groove roller 203 with respect to the electromagnetic steel sheet 500 conveyed from the material feeding uncoiler 100 and rolled. By this pressing, a groove is formed by the groove roller 203 on the surface (surface on the groove roller 203 side) of the electromagnetic steel sheet 500. The roller shaft is controlled to rise or fall in response to an instruction to a power conversion device such as a solenoid output from the control device 400. The control device 400 outputs a control signal including the width of the rise or fall control (the amount of movement of the roller shaft 301) and the direction indicating whether it is rise or fall. The control device 400 may set the amount of movement of the roller shaft 301 depending on the thickness of the electromagnetic steel sheet 500 .

[0013] The control device 400 also controls the timing of the above-mentioned upward control or downward control. The timing is controlled according to the size of the wound core. Through these controls, the control device 400 forms grooves in the main surface portion of the outer side surface 404 of the wrap portion W, the main surface portion of the outer side surface 402 of the bottom portion which is the portion facing the wrap portion W, and the main surface portions of the outer side surfaces 401, 403 of the arm portions connecting the wrap portion W and the bottom portion. The main surface portions are portions formed by planes horizontal to the circumferential direction which is the winding direction of the wound core. In FIG. 4, a groove is formed in the main surface portion D1 of the outer side surface 401 of the arm portion over the above-mentioned circumferential length d1 which is the longitudinal direction of the main surface portion, and a groove is formed in the main surface portion D4 of the outer side surface 404 of the wrap portion W over the above-mentioned circumferential length d4 which is the longitudinal direction of the main surface portion. The main surface portion D4 of the wrap portion W is a main surface portion formed by a plane horizontal to the direction of the lap joint, and the above-mentioned groove is formed in the main surface portion D4 of the wrap portion. 5 and 6, a groove is formed on the main surface portion D2 of the outer side surface 402 of the bottom portion over the circumferential length d2 which is the longitudinal direction of the main surface portion, and a groove is formed on the main surface portion D3 of the outer side surface 403 of the other arm portion over the circumferential length d3 which is the longitudinal direction of the main surface portion. Note that FIG. 5 shows a state in which no groove has yet been formed on the main surface portion D3.

[0014] On the other hand, no groove is formed in the bent portion, which is a portion located at a corner (R portion) other than the main surface portion. The bent portion is a portion formed by a curved surface bent in the circumferential direction other than the main surface portion. FIG. 4 shows that the wrap portion W has bent portions R1 and R4 at both ends in the circumferential direction, which is the longitudinal direction of the outer side surface 404. Also, as shown in FIG. 5 and FIG. 6, the wrap portion W has bent portions R2 and R3 at both ends in the circumferential direction, which is the longitudinal direction of the outer side surface 402 of the bottom portion. That is, the arm portion has bent portions R1 and R2 at both ends in the circumferential direction, which is the longitudinal direction of the outer side surface 401, and the other arm has bent portions R3 and R4 at both ends in the circumferential direction, which is the longitudinal direction of the outer side surface 403 of the other arm portion. In this way, the bent portions are formed between the main surface portion of the outer side surface 404 of the wrap portion W and the main surface portion of the outer side surface 401 of the arm portion, between the main surface portion of the outer side surface 404 of the wrap portion W and the main surface portion of the outer side surface 403 of the other arm portion, between the main surface portion of the outer side surface 402 of the bottom portion and the main surface portion of the outer side surface 401 of the arm portion, and between the main surface portion of the outer side surface 402 of the bottom portion and the outer side surface 403 of the other arm portion.

[0015] In other words, wound core C is composed of a wrap portion W where one end and the other end of electromagnetic steel sheet 500 are lap-joined, a bottom portion which is a portion facing wrap portion W, a first arm portion (e.g., an arm portion having outer side surface 401) extending from one end of the bottom portion to wrap portion W, and a second arm portion (e.g., an arm portion having outer side surface 403) extending from the other end of the bottom portion to wrap portion W, and wrap portion W, bottom portion, first arm portion, and second arm portion each have main surface portions D1, D2, D3, and D4 formed by planes horizontal to the circumferential direction which is the winding direction of wound core C, and grooves are formed in these main surface portions D1 to D4 to subdivide magnetic domains. This configuration makes it possible to prevent deterioration of iron loss characteristics due to grooves being formed in the bent portions, and to provide a stationary induction device having a wound core with less iron loss than conventional devices.

[0016] The following describes the upward and downward control of the pressure roller 202, the timing of the control, and the grooves formed by these controls. First, (1) the control device 400 controls the upward movement of the pressure roller 202 while the electromagnetic steel sheet 500 conveyed from the roller device 200 is conveyed a distance of length d1 of the main surface portion D1 of the outer side surface 401, and presses the groove roller 203 against the electromagnetic steel sheet 500. This pressing forms grooves in the main surface portion D1 of the outer side surface 401. In FIG. 4, a plurality of grooves 401d are formed over the length d1 in the main surface portion D1 of the outer side surface 401.

[0017] Next, (2) when the conveying distance of the electromagnetic steel sheet 500 reaches the most downstream position which is the end of the main surface portion D1 of the outer side surface 403, the control device 400 controls the pressure roller 202 to lower and retreats it to a position where the groove roller 203 is not pressed against the electromagnetic steel sheet 500 until it passes through the bent portion R2 which is connected to and extends to the main surface portion D1. By such control, the formation of the groove at the bent portion R2 is skipped.

[0018] Furthermore, (3) as shown in Fig. 5, while the electromagnetic steel sheet 500 is being conveyed a distance equal to the length d2 of the main surface portion D2 of the bottom portion that is connected to and extends from the skipped bent portion R2, the control device 400 again controls the pressure roller 202 to rise and presses the groove roller 203 against the electromagnetic steel sheet 500. This pressing forms grooves in the main surface portion D2 of the outer side surface 402. In Fig. 5, a plurality of grooves 402d are formed over the length d2 in the main surface portion D2 of the outer side surface 402 that is downstream of the bent portion R2 where the formation of grooves was skipped.

[0019] Next, (4) when the conveying distance of the electromagnetic steel sheet 500 reaches the most downstream position, which is the end of the main surface portion D2 of the outer side surface 402, the control device 400 controls the pressure roller 202 to lower and retreats it to a position where the groove roller 203 is not pressed against the electromagnetic steel sheet 500 until it passes through the bent portion R3 that is connected to and extends to the main surface portion D2. By such control, the formation of the groove at the bent portion R3 is skipped.

[0020] Furthermore, (5) as shown in Fig. 6, while the electromagnetic steel sheet 500 is being conveyed a distance equal to the length d2 of the main surface portion D3 of the arm portion extending from the skipped bent portion R3, the control device 400 again controls the pressure roller 202 to rise and presses the groove roller 203 against the electromagnetic steel sheet 500. This pressing forms grooves in the main surface portion D3 of the outer side surface 403. In Fig. 6, a plurality of grooves 403d are formed over the length d3 in the main surface portion D3 of the outer side surface 403 downstream of the bent portion R3 where groove formation was skipped.

[0021] Next, (6) when the conveying distance of the electromagnetic steel sheet 500 reaches the most downstream position which is the end of the main surface portion D3 of the outer side surface 403, the control device 400 controls the pressure roller 202 to lower and retreats it to a position where the groove roller 203 is not pressed against the electromagnetic steel sheet 500 until it passes through the bent portion R4 which is connected to and extends to the main surface portion D3. By such control, the formation of the groove at the bent portion R4 is skipped.

[0022] Furthermore, (7) as shown in Fig. 4, while the electromagnetic steel sheet 500 is being conveyed a distance equal to the length d4 of the main surface D4 of the wrap portion W that is connected to and extends from the skipped bent portion R4, the control device 400 again controls the pressure roller 202 to rise and presses the groove roller 203 against the electromagnetic steel sheet 500. This pressing forms grooves in the main surface D4 of the outer side surface 404. In Fig. 4, a plurality of grooves 404d are formed over the length d4 in the main surface D4 of the outer side surface 404 that is downstream of the bent portion R4 where groove formation was skipped.

[0023] The above-mentioned control of forming the grooves or skipping the formation of the grooves can be selected arbitrarily. For example, the control device 400 may perform control to skip the formation of the grooves as in the above (6) without forming the grooves on the main surface portion D4 of the wrap portion W in the above (7), thereby forming the grooves only on the main surface portions D1, D2, and D3 of the bottom and the arms other than the main surface portion D4 of the wrap portion W. That is, as shown in FIG. 11, the grooves may not be formed on the main surface portion D4 of the wrap portion W formed by a plane horizontal to the lap joint direction, but may be formed only on the main surface portions of the other parts. In FIG. 11, the main surface portion D1 of the outer side surface 401 of the arms is shown, but the grooves are also formed in the main surface portion D2 of the outer side surface 402 of the bottom and the main surface portion D3 of the outer side surface 403 of the arms in the same manner.

[0024] 15 and 16, instead of forming a groove on main surface D4 of wrap portion W, grooves of the same depth as those of the various surfaces may be formed on main surface D1 of outer side surface 401 of the arm portion, main surface D3 of outer side surface 403, and main surface D2 of outer side surface 402 of the bottom portion, as well as on folded portions R2 and R3. In Fig. 15 and Fig. 16, grooves 1501 and 1502 of the same depth as those of the main surfaces are formed on folded portions R2 and R3, respectively.

[0025] That is, the magnetic steel sheet 500 includes a lap portion W where one end and the other end are lap-joined, a bottom portion which is a portion facing the lap portion W, a first arm portion (e.g., an arm portion having an outer side surface 401) extending from a first bent portion (e.g., bent portion R2) where one end of the bottom portion is bent to one end of the lap portion W, and a second arm portion (e.g., an arm portion having an outer side surface 401) extending from a second bent portion (e.g., bent portion R3) where the other end of the bottom portion is bent to the other end of the lap portion W. For example, an arm portion having an outer side surface 403), and the bottom portion, the first arm portion, and the second arm portion each have main surface portions D1, D2, and D3 formed by planes that are horizontal in the circumferential direction, which is the winding direction of the wound core C, and the first folded portion and the second folded portion have curved surfaces formed by curved surfaces along the circumferential direction, and grooves for subdividing magnetic domains are formed in the main surface portions D1 to D3 and the curved surfaces (the curved surfaces R2 and R3).

[0026] As described above, by controlling (1) to (7), grooves for dividing magnetic domains are not formed on the outer side surface of the wound core at both ends of the wrap portion, the bottom portion facing the wrap portion, and the bent portion formed between the arm portions extending from the bottom, and grooves are formed only on these main surfaces. Therefore, it is possible to prevent deterioration of iron loss characteristics due to the formation of grooves in the bent portions. In addition, by controlling not to form grooves in the wrap portion W (main surface portion D4 and the bent portions R1, R4 at both ends) of the wound core, it is possible to reduce leakage flux generated in the wrap portion where the flow of magnetic flux is disturbed and magnetic flux transfer occurs, and to prevent an increase in iron loss. As a result, it is possible to provide a stationary induction device having a wound core with less iron loss than before.

[0027] In the above embodiment, a wound core with low iron loss is constructed by forming grooves in the main surface portions other than the bent portions. However, the iron loss may be reduced depending on the depth of the grooves in the wound core, taking into consideration the portions of the wound core. For example, in the above (2), (4), and (6) where the formation of the grooves is skipped, the control device 400 may control the pressure roller 202 to have a pressing force smaller than the pressing force of the pressure roller 202 when the grooves are formed in the above (1), (3), and (5). FIG. 7 shows that the bent portions R1 and R4 have grooves 701 and 704 that are shallower than the grooves formed in the main surface portions D1 and D4 of the outer side surfaces 401 and 404. FIG. 8 shows that the bent portions R2 and R3 have grooves 702 and 703 that are shallower than the grooves formed in the main surface portions D2 and D3 of the outer side surfaces 402 and 403. In other words, the wrap portion W has a main surface portion D4 of the wrap portion W formed by a plane horizontal to the direction of the wrap joint, and a curved surface of the wrap portion W (curved surfaces of the bent portions R1, R4) formed by curved surfaces along the circumferential direction at one end and the other end of the wrap portion W, with a groove formed in the main surface portion D4 of the wrap portion W, and a groove shallower than the groove formed in the wrap portion curved surface.

[0028] This type of control makes it possible to reduce the amount of control required for raising and lowering the pressure roller 202 at the bent portion, thereby reducing the energy consumption of the iron core manufacturing apparatus 1000 and providing a stationary induction device having a wound core with less iron loss than conventional devices.

[0029] Furthermore, even when reducing iron loss according to the depth of the grooves in the above-mentioned locations, the control device 400 may perform control so as not to form grooves in the wrap portion W. In Figures 12 and 13, the above-mentioned shallow grooves are formed in the bent portions R2 and R3, while the above-mentioned shallow grooves are not formed in the bent portions R1 and R4 at both ends of the wrap portion W, and no grooves are formed in the main surface portion D4 of the wrap portion W.

[0030] In other words, the wound core C includes a lap portion W where one end and the other end of the electromagnetic steel sheet 500 are lap-joined, a bottom portion which faces the lap portion W, a first arm portion (e.g., an arm portion having an outer side surface 401) extending from a first bent portion (e.g., a bent portion R2) where one end of the bottom portion is bent to the lap portion W, and a second arm portion (e.g., an arm portion having an outer side surface 401) extending from a second bent portion (e.g., a bent portion R3) where the other end of the bottom portion is bent to the lap portion W. 03) and a base portion, a first arm portion, and a second arm portion each having a main surface portion D1, D2, D3 formed by a plane horizontal to the circumferential direction, which is the winding direction of the wound core C, the first folded portion and the second folded portion each having a curved surface along the circumferential direction, grooves for subdividing magnetic domains are formed in the main surface portions D1, D2, D3, and the curved surfaces (for example, the curved surfaces of the folded portions R2, R3) have grooves that are shallower than the grooves in the main surface portions.

[0031] This type of control reduces the amount of control in the upward and downward control of the pressure roller 202 at the bent portion, thereby reducing the energy consumption of the iron core manufacturing apparatus 1000, while preventing an increase in iron loss due to leakage flux in the wrap portion, and making it possible to provide a stationary induction device with a wound core that has less iron loss than conventional devices.

[0032] In the above embodiment, the grooves are formed on the outer side surface of the wound core, but as shown in FIG. 9, grooves may be formed on the main surface of the inner side surface of the wound core. In FIG. 9, a plurality of grooves 403d' are formed on the main surface portion D3' of the inner side surface 403' that is on the inside of the stacking direction with respect to the outer side surface 403 of the arm portion, and a plurality of grooves 402d' are formed on the main surface portion D2' of the inner side surface 402' with respect to the outer side surface 402 of the bottom portion. FIG. 9 illustrates the case where grooves are formed in these locations, but similar grooves are also formed on the main surface portion of the inner side surface with respect to the outer side surface 401 of the arm portion and the main surface portion of the inner side surface with respect to the outer side surface 404 of the wrap portion W. For example, as shown in FIG. 19, a plurality of grooves 401d' and 404d' are formed on the main surface portion D1' of the inner side surface 401' with respect to the outer side surface 401 of the arm portion and the main surface portion D4' of the inner side surface 404' with respect to the outer side surface 404 of the wrap portion W, respectively.

[0033] That is, grooves may be formed in each main surface of the wrap portion W, the bottom, the first arm portion (e.g., the arm portion having outer side surface 401), and the inner side surface of the second arm portion (e.g., the arm portion having outer side surface 403). With this configuration, it is possible to provide a stationary induction device having a wound core with less iron loss than conventional devices, while preventing the grooves formed in the wound core from getting caught in the coil when inserting the wound core into the coil.

[0034] When forming grooves in the main surfaces of the inner side surface described above, grooves may be formed only in the bottom other than the main surface of the inner side surface of wrap portion W, the main surface of the inner side surface of each of the first arm portion (e.g., the arm portion having outer side surface 401), and the main surface of the second arm portion (e.g., the arm portion having outer side surface 403). In FIG. 14, groove 401d' is formed in main surface portion D1' of inner side surface 401' relative to outer side surface 401 of the arm portion, while no groove is formed in main surface portion D4' of inner side surface 404' of wrap portion W. With this configuration, it is further possible to prevent an increase in iron loss due to leakage flux in the wrap portion, and it is possible to provide a stationary induction device having a wound core with less iron loss than conventional devices.

[0035] Furthermore, as shown in Fig. 10, the above-mentioned groove formation on the main surface of the inner side surface and the groove formation on the outer side surface may be combined. Fig. 10 shows that grooves are formed on the main surface D3' of the inner side surface 403' of the arm portion, the main surface D2' of the inner side surface 402' of the bottom portion, and the main surface D1' of the inner side surface 401' of the arm portion (not shown), and a groove is formed on the main surface D4 of the outer side surface 404 of the wrap portion W. In addition to this combination, a combination is also possible in which grooves are formed on the main surfaces of the outer side surfaces of the bottom portion and the arm portions (first arm portion and / or second arm portion) while a groove is formed on the main surface of the inner side surface of the wrap portion W.

[0036] As shown in Figures 9 and 10, when a groove is formed in the main surface of the inner side surface, a shallower groove than that in the main surface may be formed in the bent portion as described with reference to Figures 7 and 8. In Figures 17 and 18, grooves are formed in the main surface of the inner side surface of each of the bottom, the first arm portion (e.g., the arm portion having the outer side surface 401), and the second arm portion (e.g., the arm portion having the outer side surface 403), and further, a groove 1801 (shown by a two-dot chain line) shallower than the above groove is formed in the inner side surface R3' of the bent portion R3. The above shallow groove similar to that in the inner side surface R3' is also formed in the inner side surface of the bent portion R2. With this configuration, it is possible to prevent the groove formed in the wound core from getting caught in the coil when inserting the wound core into the coil, and it is also possible to reduce the amount of control in controlling the ascent and descent of the pressure roller 202 at the bent portion, thereby reducing the energy consumption of the core manufacturing apparatus 1000 and providing a stationary induction device with a wound core that has less iron loss than conventional devices.

[0037] Furthermore, as shown in FIG. 19, when multiple grooves 404d' are formed in the main surface portion D4' of the inner side surface 404' of the wrap portion W, and grooves shallower than the above-mentioned grooves are formed in the inner side surface R1' at both ends and the inner side surface R4' (not shown), the above-mentioned effect can be obtained while further preventing an increase in iron loss due to the generation of leakage magnetic flux in the wrap portion.

[0038] The present invention is not limited to the above-described embodiments as they are, and in the implementation stage, the components can be modified and embodied within the scope of the gist of the present invention, or multiple components disclosed in the above-described embodiments can be appropriately combined. [Explanation of symbols]

[0039] 1000 Iron core manufacturing equipment 100 Material feed uncoiler 200 Roller device 202 Pressure roller 203 Grooved roller 204 Groove component 300 Material winding uncoiler 301 Roller shaft 400 Control device 401~404 Outer side 401d~404d Groove 701~704 Shallow Groove D1~D4 Main surface part R1~R4 bending part D1'~D4' Main surface part (inside) R1'~R4' Bend section (inside) 401d'~404d' Groove (inside) 1501, 1502, groove (bending part) 1801, 1802 Shallow groove (inner) W Wrap 410 Processor 420 Memory 500 Electrical steel sheet

Claims

1. A stationary induction machine having a wound core made of electromagnetic steel sheets, The wound core is the electrical steel sheet is configured with a lap portion at which one end and the other end are lap-joined, a bottom portion which faces the lap portion, a first arm portion extending from one end of the bottom portion to the lap portion, and a second arm portion extending from the other end of the bottom portion to the lap portion, The bottom portion, the first arm portion, and the second arm portion each have The wound core has a main surface portion formed by a plane that is horizontal in a circumferential direction, which is a winding direction of the wound core, A groove for dividing a magnetic domain is formed on the main surface. A stationary induction device characterized in that

2. The wrap portion is A lap portion has a main surface formed by a plane horizontal to the direction of the lap joint, The groove is formed on the main surface of the wrap portion.

2. The stationary induction machine according to claim 1 .

3. The groove is formed on the main surface of the inner side surface of each of the bottom portion, the first arm portion, and the second arm portion, 2. The stationary induction machine according to claim 1 .

4. The groove is A main surface of the inner side of the wrap portion is formed.

3. The stationary induction machine according to claim 2.

5. A stationary induction machine having a wound core made of electromagnetic steel sheets, The wound core is the electrical steel sheet is configured with a lap portion at which one end and the other end are lap-joined, a bottom portion which faces the lap portion, a first arm portion which extends from a first bent portion at which one end of the bottom portion is bent to the lap portion, and a second arm portion which extends from a second bent portion at which the other end of the bottom portion is bent to the lap portion, The bottom portion, the first arm portion, and the second arm portion each have The wound core has a main surface portion formed by a plane that is horizontal in a circumferential direction, which is a winding direction of the wound core, The first bent portion and the second bent portion are A curved surface along the circumferential direction, A groove for dividing a magnetic domain is formed on the main surface, and a groove shallower than the groove on the main surface is formed on the curved surface. A stationary induction device characterized in that

6. The wrap portion is a wrap portion main surface portion formed by a plane horizontal to the direction of the wrap joint, and a wrap portion curved surface formed by a curved surface along the circumferential direction at one end and the other end of the wrap portion, The groove is formed on the main surface of the wrap portion, and the shallow groove is formed on the curved surface of the wrap portion.

6. The stationary induction machine according to claim 5.

7. The groove is formed on the main surface of the inner side surface of each of the bottom portion, the first arm portion, and the second arm portion, 6. The stationary induction machine according to claim 5.

8. The groove is A main surface of the inner side of the wrap portion is formed.

7. The stationary induction machine according to claim 6.

9. A stationary induction machine having a wound core made of electromagnetic steel sheets, The wound core is the electrical steel sheet is configured with a lap portion where one end and the other end are lap-joined, a bottom portion which faces the lap portion, a first arm portion which extends from a first bent portion where one end of the bottom portion is bent to one end of the lap portion, and a second arm portion which extends from a second bent portion where the other end of the bottom portion is bent to the other end of the lap portion, The bottom portion, the first arm portion, and the second arm portion each have a main surface portion formed by a plane that is horizontal in a circumferential direction that is a winding direction of the wound core, The first bent portion and the second bent portion are A curved surface is formed along the circumferential direction, A groove for dividing a magnetic domain is formed on the main surface and the curved surface. A stationary induction device characterized in that

10. The groove is formed on the main surface of the inner side surface of each of the bottom portion, the first arm portion, and the second arm portion, 10. The stationary induction machine according to claim 9.

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