Method for manufacturing laminated iron core and laminated iron core

Abstract

Provided is a method for manufacturing a laminated iron core in which a lamination height can be reliably adjusted after iron core pieces are integrated. A plurality of iron core pieces 3 are laminated, and the laminated iron core pieces are connected and integrated by a first welding portion 5 formed by a first welding between projections 15. The lamination height of the integrated iron core pieces 3 is measured, and, on the basis of the measured lamination height, an add-on iron core piece 7 equipped with an unwelded projection 15 is laminated to the integrated iron core pieces 3 to make the entire lamination height within a predetermined lamination height range. An iron core piece 3 at an end portion in the lamination direction among the integrated iron core pieces 3 is provided with a starting end 5a of the first welding portion 5. A second welding portion 9 is formed by a second welding crossing from the starting end 5a of the first welding portion 5 of the iron core piece 3 at the end portion to the projection 15 of the add-on iron core piece 7, thereby connecting the iron core piece 3 at the end portion and the add-on iron core piece 7 to each other.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminated core used for an electric motor or the like and a laminated core.

Background Art

[0002] As a conventional method for manufacturing a laminated core, there is a method of manufacturing a laminated core by laminating a plurality of core blocks made of electromagnetic steel sheets, which are a plurality of core pieces, as in Patent Document 1.

[0003] In this manufacturing method, when forming a plurality of core blocks, the number of electromagnetic steel sheets is determined so that the laminated height of the laminated core blocks is smaller than the target height. Then, a plurality of core blocks formed of the determined number of electromagnetic steel sheets are laminated. Electromagnetic steel sheets are added according to the difference between this laminated height and the target height, and the whole is integrated together with the plurality of core blocks to manufacture a laminated core.

[0004] In such a manufacturing method, by adjusting the laminated height when integrating a plurality of electromagnetic steel sheets, a laminated core having a laminated height within the target height or its allowable range can be obtained. However, it may be desired to adjust the laminated height after integrating core pieces such as a plurality of electromagnetic steel sheets.

[0005] On the other hand, if core pieces are separately laminated and joined, it is possible to adjust the laminated height. However, in this case, there is a risk that problems may occur in the bonding strength or the like of the separately laminated core pieces, and the reliable adjustment of the laminated height has not been achieved.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem we are trying to solve is that it is not possible to reliably adjust the stacking height after integrating multiple iron core pieces. [Means for solving the problem]

[0008] The present invention involves stacking multiple iron core pieces, and the stacked iron core pieces but The stacked core pieces are joined together by a first weld formed by a first weld extending between the planned weld portions, and the entire stacked core pieces are integrated. The stacking height of the integrated core pieces is measured, and based on the measured stacking height, additional core pieces with unwelded planned weld portions are stacked on the integrated core pieces to bring the overall stacking height within a predetermined range. The first weld is formed over the entire stacking direction of the integrated iron core pieces, In the aforementioned integrated iron core piece The aforementioned The iron core piece at the end in the stacking direction is the starting point of the first weld. of The beginning of the first weld of the end of the iron core piece and By a second weld extending to the planned welding area of ​​the aforementioned additional iron core piece, At least the starting end of the first weld and the planned welding portion of the iron core piece for stacking have melted and solidified. The present invention provides a method for manufacturing laminated iron cores, which involves forming a second weld and joining the end core piece with the additional core piece.

[0009] Furthermore, the present invention relates to a plurality of iron core pieces that are stacked and joined together to form a single unit, and a starting end located at least on the end iron core piece in the stacking direction, which joins at least a portion of the plurality of iron core pieces. and formed over the entire stacking direction of the integrated iron core piece A first welded section, an additional core piece stacked on the integrated core piece, and a section extending from the additional core piece to the starting end of the first welded section. Furthermore, at least the starting end of the first weld and the planned welding portion of the iron core piece for stacking melt and solidify. The present invention provides a laminated core comprising a second welded portion for joining the end core piece to the additional core piece. [Effects of the Invention]

[0010] According to the present invention, the stacking height can be reliably adjusted after integrating multiple iron core pieces. [Brief explanation of the drawing]

[0011] [Figure 1]Figure 1 is a schematic plan view showing a laminated iron core according to Embodiment 1 of the present invention. [Figure 2] Figure 2 is an enlarged perspective view showing part II of Figure 1. [Figure 3] Figure 3(A) is an enlarged plan view showing the area around the protrusion of the core piece before the formation of the first weld, and Figure 3(B) is an enlarged plan view showing the area around the first weld of the core piece. [Figure 4] Figure 4(A) is a schematic side view showing the laminated core pieces before the formation of the second weld, and Figure 4(B) is a schematic side view showing the laminated core after the formation of the second weld. [Figure 5] Figure 5(A) is a schematic cross-sectional view showing an enlarged portion of the core piece for stacking and the laminated core piece before the formation of the second weld, and Figure 5(B) is a schematic cross-sectional view showing an enlarged portion of the laminated core corresponding to Figure 5(A) after the formation of the second weld. [Figure 6] Figure 6 is a schematic perspective view showing an enlarged portion of the core pieces for stacking and the laminated core pieces before the formation of the second weld. [Figure 7] Figure 7 is a process diagram showing the manufacturing method of a laminated iron core according to Embodiment 1 of the present invention. [Figure 8] Figure 8(A) is a schematic side view showing the laminated core piece before the formation of the second weld according to Embodiment 2 of the present invention, and Figure 8(B) is a schematic side view showing the laminated core after the formation of the second weld. [Figure 9] Figure 9(A) is a schematic side view showing a laminated core piece before the formation of the second weld, relating to a modified example of Example 2, and Figure 9(B) is a schematic side view showing the laminated core after the formation of the second weld. [Figure 10] Figure 10(A) is a schematic side view showing a laminated core piece before the formation of the second weld, relating to another modification of Example 2, and Figure 10(B) is a schematic side view showing the laminated core after the formation of the second weld. [Figure 11] Figure 11(A) is a schematic side view showing the laminated core piece before the formation of the second weld according to Embodiment 3 of the present invention, and Figure 11(B) is a schematic side view showing the laminated core after the formation of the second weld. [Figure 12]FIG. 12(A) is a schematic side view showing a laminated iron core piece before forming a second welded portion according to a modification of Example 3, and FIG. 12(B) is a schematic side view showing the laminated iron core after forming the second welded portion.

Mode for Carrying Out the Invention

[0012] The object of reliably adjusting the stacking height after integrating a plurality of iron core pieces is achieved by forming a second welded portion extending from the start end of the first welded portion or the planned welding portion of the stacked and integrated iron core pieces to the planned welding portion of the additional iron core piece.

[0013] That is, in the method of manufacturing the laminated iron core 1, a plurality of iron core pieces 3 are stacked, and the entire stacked iron core pieces 3 are integrated. In this integration, at least a part of the stacked iron core pieces 3 has a planned welding portion 15 and is joined by a first welded portion 5 formed by a first welding across the planned welding portions 15.

[0014] Then, the stacking height of the integrated iron core pieces 3 is measured, and based on the measured stacking height, an additional iron core piece 7 having a planned welding portion 15 that is not welded is stacked on the integrated iron core pieces 3 so that the overall stacking height is within a predetermined stacking height range.

[0015] The iron core piece 3 at the end in the stacking direction in the integrated iron core pieces 3 has the start end 5a of the first welded portion 5 or a planned welding portion 15 that is not welded, and a second welded portion 9 is formed by a second welding across the start end 5a of the first welded portion 5 or the planned welding portion 15 that is not welded of the end iron core piece 3 and the planned welding portion 15 of the additional iron core piece 7, thereby joining the end iron core piece 3 and the additional iron core piece 7.

[0016] The planned welding portion 15 can adopt various shapes in which the outer peripheral shape or the inner peripheral shape is changed with respect to other portions as the portion where welding is performed. For example, the planned welding portion 15 may be a radial protrusion provided on the iron core pieces 3 and 7.

[0017] There is a gap 17 in the stacking direction between the starting end 5a of the first weld 5 of the end core piece 3 and the planned weld portion 15 of the stacked additional core piece 7, and the starting end 5a may melt and solidify together with the planned weld portion 15 of the additional core piece 7 by the second weld.

[0018] The first weld 5 may be formed over the entire stacking direction of the integrated iron core pieces 3.

[0019] The number of second welds 9 may be the same as the number of first welds 5.

[0020] The laminated core 1 comprises a plurality of core pieces 3, a first weld 5, an additional core piece 7, and a second weld 9. The core pieces 3 are laminated and joined together to form a single unit. The first weld 5 has its starting end 5a located at least on the end core piece 3 in the lamination direction. The additional core piece 7 is laminated onto the integrated core piece 3. The second weld 9 extends from the additional core piece 3 to the starting end 5a of the first weld 5 and joins the additional core piece 7 to the end core piece 3. [Examples]

[0021] [Laminated iron core] Figure 1 is a schematic plan view showing a laminated iron core according to Embodiment 1 of the present invention. Figure 2 is a perspective view showing an enlarged view of part II of Figure 1.

[0022] The laminated core 1 in this embodiment is a stator core used on the stator side of an electric motor or generator, as shown in Figures 1 and 2. The laminated core 1 may also be a rotor core used on the rotor side. This laminated core 1 comprises a plurality of core pieces 3, a first welded section 5, additional core pieces 7, and a second welded section 9.

[0023] In Figure 1, since the core piece 3 has the same shape as the core piece 7, only the symbol for core piece 3 is shown by placing it in parentheses next to the symbol for core piece 7. Similarly, since the first weld 5 is located at the same position as the second weld 9 in the circumferential direction, only the symbol for the first weld 5 is shown by placing it in parentheses next to the symbol for the second weld 9.

[0024] Each of the multiple core pieces 3 is made of electrical steel sheet and in this embodiment forms an annular plate. Alternatively, the core pieces 3 may be formed as arc-shaped plates, and multiple arc-shaped plates may be joined in the circumferential direction to form a single annular plate.

[0025] Multiple core pieces 3 are stacked to form a laminated core piece 11. The core pieces 3 of the laminated core piece 11 are joined together by multiple first welds 5.

[0026] Multiple first welds 5 are arranged at intervals around the outer circumference of the laminated core piece 11. In the case of a rotor core where the laminated core 1 is used on the rotor side, the first welds 5 can also be formed on the inner circumference of the laminated core piece 11.

[0027] The circumferential position and number of the first welds 5 are not limited, but in this embodiment, the first welds 5 are formed in 12 recesses 13 in the circumferential direction at 30° intervals.

[0028] Figure 3(A) is an enlarged plan view showing the area around the protrusion of the core piece before the formation of the first weld, and Figure 3(B) is an enlarged plan view showing the area around the first weld of the core piece. Figure 4(A) is a schematic side view showing the laminated core piece before the formation of the second weld, and Figure 4(B) is a schematic side view showing the laminated core after the formation of the second weld. In Figure 3, the core piece 7 and the second weld 9 are indicated only by their symbols, enclosed in parentheses, corresponding to the symbols of the core piece 3 and the first weld 5, respectively.

[0029] Before welding the laminated core pieces 11, as shown in Figure 3(A), welding projections 15 are formed in the recesses 13, continuous in the lamination direction, as areas to be welded. The first welded area 5 is formed by melting and solidifying the projections 15 of the laminated core pieces 11 through the first welding, as shown in Figure 3(B).

[0030] Therefore, the first welded portion 5 is formed by a first weld extending between the protrusions 15, which are projections 15 that are to be welded, and at least a portion of the laminated core pieces 3 of the laminated core piece 11. In this embodiment, all of the core pieces 3 of the laminated core piece 11 have protrusions 15. The first welded portion 5 is formed over all of these protrusions 15.

[0031] Therefore, as shown in Figure 4(A), the first weld 5 is formed over the entire stacking direction of the laminated core pieces 11 before the formation of the second weld 9. However, the first weld 5 may be formed only in a part of the stacking direction of the laminated core pieces 11, for example, between an end core piece 3 and an adjacent core piece 3. In this case, the other core pieces 3 can be joined by a well-known crimping or the like.

[0032] Furthermore, the first welded joint 5 only needs to be separated at both ends in the lamination direction, and does not need to be strictly aligned with the lamination direction. The lamination direction refers to the axial direction along the axis of the laminated core 1. In the following, the circumferential direction refers to the direction around the axis of the laminated core 1, and the radial direction refers to the direction along the diameter of the laminated core 1.

[0033] The first welding can be performed by, for example, laser welding, TIG welding, or EB welding. The projection 15 only needs to protrude radially from the outer circumference of the core piece 3. However, the area to be welded is only the part where the outer circumference shape of the core piece 3, such as the diameter or thickness, is changed compared to other parts. For this reason, various shapes can be used for the area to be welded. Note that when the first welded area 5 is formed on the inner circumference of the laminated core 1, the area to be welded is the inner circumference shape of the core piece 3 that is changed compared to other parts.

[0034] Figure 5(A) is a schematic cross-sectional view showing an enlarged portion of the core piece 7 for stacking and the laminated core piece 11 before the formation of the second weld 9, and Figure 5(B) is a schematic cross-sectional view showing an enlarged portion of the laminated core 1 corresponding to Figure 5(A) after the formation of the second weld 9. Figure 6 is a schematic perspective view showing an enlarged portion of the core piece 7 for stacking and the laminated core piece 11 before the formation of the second weld 9.

[0035] As shown in Figures 4(A), 5(A), and 6, the starting end 5a of the first weld 5 is located on the end core piece 3 in the stacking direction before the formation of the second weld 9. The surface of the starting end 5a of the first weld 5 is arc-shaped. As a result, the dimension of the first weld 5 in the stacking direction decreases as the starting end 5a of the first weld 5 extends radially outward from the main body portion 3a of the end core piece 3.

[0036] Additional core pieces 3 are stacked on top of the laminated core piece 11. The additional core pieces 7 have the same configuration as the core pieces 3 of the laminated core piece 11, as described above. Note that in Figure 4, the additional core pieces 7 are distinguished from the core pieces 3 by hatching, but this does not show a cross-section. The same applies to Figures 8 to 12.

[0037] The additional core pieces 7 are stacked on top of the laminated core pieces 11 to bring the overall height within a predetermined stacking height range. The predetermined stacking height range refers to the allowable range of the target value for the stacking height. The number of additional core pieces 7 is set appropriately according to the difference between the stacking height of the laminated core pieces 11 and the lower limit of the predetermined stacking height range, as well as the plate thickness of the core pieces 7.

[0038] The additional core piece 7 is stacked on the end core piece 3 where the starting end 5a of the first weld 5 of the stacked core piece 11 is located. This core piece 7 and the end core piece 3 are joined by a second weld 9 as shown in Figures 4(B) and 5(B).

[0039] The second welds 9 are formed in 12 recesses 13 in the circumferential direction at 30° intervals, as shown in Figures 1 and 2. The same number of second welds 9 as the number of first welds 5 are provided and each is connected to a first weld 5. Note that the number of second welds 9 may be less than the number of first welds 5.

[0040] As shown in Figures 3(A) and (B), Figure 4(B), and Figure 5(B), the second weld 9 extends from the additional core piece 7 to the starting end 5a of the first weld 5 and connects the additional core piece 7 to the end core piece 3. This second weld 9 is formed by a second weld that extends from the starting end 5a of the first weld 5 of the end core piece 3 of the laminated core piece 11 to the projection 15 of the additional core piece 7. The second weld can be performed by laser welding, TIG welding, EB welding, etc., similar to the first weld.

[0041] The second weld 9 has an arc-shaped surface, similar to the first weld 5. This second weld 9 extends in the stacking direction from the additional core piece 7, through the end core piece 3, and then to several more core pieces 3 from the end. However, the second weld 9 only needs to be formed from the additional core piece 7 to the end core piece 3.

[0042] In the additional core pieces 7 and the end core pieces 3, a second weld 9 is formed from a portion of the main body 7a and 3a of the core pieces 7 and 3. As a result, the second weld 9 extends radially inward from the first weld 5. In addition, in the end core pieces 3, the starting end 5a of the first weld 5 is melted and solidified by the second weld, so the first weld 5 is replaced by the second weld 9. In several core pieces 3 excluding the end pieces, the second weld 9 is positioned to cover the outer circumference of the first weld 5, and a joint is formed at both the second weld 9 and the first weld 5.

[0043] [Manufacturing method for laminated iron cores] Figure 7 is a process diagram showing the manufacturing method of the laminated core 1. In this embodiment, the manufacturing method involves welding a laminated core piece 11, which is formed by stacking multiple core pieces 3.

[0044] In the first welding step S1 shown in Figure 7, a first welded joint 5 is formed on the multiple stacked core pieces 3 of the laminated core piece 11, as shown in Figure 4(A). That is, the first welded joint 5 is formed by first welding across the protrusions 15 of the multiple stacked core pieces 3. As a result, at least a portion, and in this embodiment all, of the stacked core pieces 3 are joined at the first welded joint 5. Therefore, the entire core pieces 3 of the laminated core piece 11 are integrated. Note that the core pieces 3 of the laminated core piece 11 may be joined to each other in advance by crimping or adhesive.

[0045] During the first welding, multiple core pieces 3 are stacked together as a laminated core piece 11, and this laminated core piece 11 is pressurized in the stacking direction. Then, using a torch such as a fiber laser welding machine, the first welding is performed on the protrusions 15 of the core pieces 3 of the pressurized laminated core piece 11 to form the first welded section 5.

[0046] The first welding is performed from one end to the other in the lamination direction. As a result, the starting end 5a of the first weld 5 is formed at one end of the laminated core piece 11 in the lamination direction, as shown in Figures 4(A), 5(A), and 6.

[0047] Next, in the height measurement step S2, the stacking height of the laminated core pieces 11, that is, the stacking height of the integrated core pieces 3, is measured. The measurement of the stacking height is not limited to any particular method, but for example, it is performed by applying pressure to the laminated core pieces 11 in the stacking direction using a well-known method.

[0048] If the measured stacking height is within the range of a predetermined stacking height, the process proceeds to the next step S3, such as other inspections. On the other hand, if the measured stacking height is less than the lower limit of the predetermined stacking height range, the stacking process S4 is performed.

[0049] In the stacking process S4, based on the measured stacking height, one or more stacking core pieces 7 having unwelded protrusions 15 are stacked on the stacked core piece 11, as shown in Figures 4(A), 5(A), and 6. In this embodiment, one core piece 7 is stacked on the stacked core piece 11. As a result, the overall stacking height of the stacked core piece 11 and the stacking core pieces 7 falls within a predetermined stacking height range.

[0050] The lamination of these core pieces 7 is performed on the end of the core piece 3 having the starting end 5a of the first weld 5, as described above. In this state, there is a gap 17 in the lamination direction between the projection 15 of the laminated additional core piece 7 and the starting end 5a of the first weld 5.

[0051] The gap 17 can be naturally formed between the starting end 5a of the first weld 5 and the projection 15 of the reinforcement core piece 7, depending on the direction of welding. However, the gap 17 may also be formed by processing the starting end 5a of the first weld 5. Furthermore, the first weld 5 may be formed in a way that does not create the gap 17.

[0052] Next, a second weld 9 is formed by a second weld extending from the projection 15 of the additional core piece 7 to the starting end 5a of the first weld 5 of the laminated core piece 11.

[0053] The second weld is performed in the same manner as the first weld. However, the welding power and focal size of the second weld are smaller than those of the first weld. This allows for a denser weld in the second weld. It is also possible to use the same or greater welding power and focal size for the second weld as for the first weld.

[0054] Furthermore, the welding speed of the second weld is greater than that of the first weld. This suppresses rapid melting in the second weld, allowing for a denser weld. Note that welding speed refers to the speed of focus movement. The welding speed of the second weld can also be equal to or less than that of the first weld. The second weld may be performed in a back-and-forth (overlap) manner, and a sufficient amount of melting can be ensured by increasing the number of back-and-forth (overlap) passes.

[0055] During the second welding, as shown in Figure 5(B), a portion of the main body 7a adjacent to the projection 15 of the additional core piece 7 melts. Also, a portion of the first weld 5, including the starting end 5a, melts together with the projection 15 of the additional core piece 7. Therefore, the molten projection 15 of the additional core piece 7, a portion of the main body 7a, and a portion of the first weld 5, including the starting end 5a, solidify to form the second weld 9.

[0056] Furthermore, the second welding can be performed by melting and solidifying at least the projection 15 of the additional iron core piece 7 and the starting end 5a of the first weld 5 to form the second weld 9, as described above.

[0057] Thus, in this embodiment, the stacking height of the stacked core pieces 11 can be adjusted by integrating multiple core pieces 3 and then stacking and joining additional core pieces 7. After adjusting the stacking height, the process returns to the height measurement step S2, but it is also possible to proceed directly to the next step S4 without returning to the height measurement step S2.

[0058] If the stacking height in the height measurement step S2 is within the range of a predetermined stacking height, the stacked core piece 11 with the adjusted stacking height is used as the stacked core 1 and the process proceeds to the next step S3.

[0059] As described above, in the manufacturing method of the laminated core 1, the second weld 9 is formed by a second weld that extends from the projection 15 of the additional core piece 7 to a portion of the first weld 5 including the starting end 5a. Therefore, the bonding strength of the additional core piece 7 to the end core piece 3 can be improved.

[0060] Generally, welded joints are prone to shape defects at the ends, and poor connections are likely to occur when connecting other welded joints. In this embodiment, since the second welded joint 9 is connected to the starting end 5a of the first welded joint 5, poor connections are less likely to occur, and the joint strength can be improved. Therefore, the stacking height can be reliably adjusted after integrating multiple iron core pieces 3.

[0061] Furthermore, since the stacking height is reliably adjusted after integrating multiple core pieces 3, variations in stacking height due to adjustment are reduced, improving the accuracy of stacking height adjustment. Moreover, because the number of additional core pieces 7 is significantly less than the number of core pieces 3, variations in stacking height due to adjustment can be reduced even more reliably.

[0062] During the second welding, a gap 17 in the stacking direction is provided between the projection 15 of the stacked additional core piece 7 and the starting end 5a of the first weld 5. This allows for easier second welding by targeting the projection 15 of the additional core piece 7, and enables the second weld 9 to be stabilized into the desired shape. Furthermore, the presence or absence of the gap 17 makes it easier to determine whether or not the second weld 9 has been formed, ensuring reliable formation of the second weld 9. As a result, the bonding strength of the additional core piece 7 can be improved more reliably.

[0063] Furthermore, since the second weld 9 is formed at the end core piece 3 with the melting of the first weld 5 and bonding with the first weld 5, the integrity of the end core piece 3 and the additional core piece 7 is enhanced, and the bonding strength of the additional core piece 7 can be improved more reliably.

[0064] Since the number of second welds 9 is the same as the number of first welds 5, the bonding strength of the additional core pieces 7 can be improved. [Examples]

[0065] Figure 8(A) is a schematic side view showing a laminated core piece before the formation of the second weld according to Embodiment 2 of the present invention, and Figure 8(B) is a schematic side view showing a laminated core after the formation of the second weld. In Embodiment 2, the basic configuration is the same as that of Embodiment 1, so the same reference numerals are used for corresponding components and redundant explanations are omitted.

[0066] In this embodiment, the first welded portion 5 that integrates multiple core pieces 3 of the laminated core piece 11 includes a full welded portion 19 and a partial welded portion 21.

[0067] The entire weld 19 is a weld formed over the entire stacking direction of the multiple integrated core pieces 3 of the laminated core piece 11, and corresponds to the first weld 5 in Example 1.

[0068] The partial weld 21 is a weld provided in a portion of the stacking direction of the multiple integrated core pieces 3 of the laminated core piece 11. The portion of the stacking direction in which the partial weld 21 is located refers to the portion of the integrated core piece 3 that extends to the end of the core piece 3 in the stacking direction and at least the core piece 3 adjacent to it. Therefore, the partial weld 21 can suppress the peeling of the end core piece 3.

[0069] The second weld 9 is connected to the partial weld 21 of the first weld 5. That is, the second weld 9 is formed by a second weld extending from the starting end 21a of the partial weld 21 of the first weld 5 to the projection 15 of the reinforcement core piece 7. Therefore, the second weld 9 can be formed using the partial weld 21.

[0070] In this embodiment, the number of additional core pieces 7 is two. The starting end 21a of the partial weld 21 has an arc-shaped surface, similar to the starting end 19a of the full weld 19. Otherwise, it is the same as in Embodiment 1.

[0071] In this second example, the same effects and advantages as in the first example can be achieved.

[0072] [Differentiation] Figure 9(A) is a schematic side view showing a laminated core piece before the formation of the second weld, relating to a modified example of Example 2, and Figure 9(B) is a schematic side view showing the laminated core after the formation of the second weld. Figure 10(A) is a schematic side view showing a laminated core piece before the formation of the second weld, relating to another modified example of Example 2, and Figure 10(B) is a schematic side view showing the laminated core after the formation of the second weld.

[0073] In the modified example shown in Figure 9, the second weld 9 is connected to the entire weld 19 of the first weld 5. Therefore, the second weld 9 is formed by a second weld extending from the starting end 19a of the entire weld 19 of the first weld 5 to the projection 15 of the reinforcement core piece 7.

[0074] In the modified example shown in Figure 10, the second weld 9 is connected to both the full weld 19 and the partial weld 21 of the first weld 5. Therefore, the second weld 9 is formed by a second weld extending from the starting end 19a of the full weld 19 of the first weld 5 to the projection 15 of the additional core piece 7, and by a second weld extending from the starting end 21a of the partial weld 21 of the first weld 5 to the projection 15 of the additional core piece 7.

[0075] Even with this modified configuration, the same effects and advantages as in Example 1 can be achieved. Furthermore, in the modified configuration shown in Figure 10, the bonding strength of the additional iron core pieces 7 can be improved. [Examples]

[0076] Figure 11(A) is a schematic side view showing the laminated core piece before the formation of the second weld according to Embodiment 3 of the present invention, and Figure 11(B) is a schematic side view showing the laminated core after the formation of the second weld. In Embodiment 3, the basic configuration is the same as that of Embodiment 1, so the same reference numerals are used for corresponding components and redundant explanations are omitted.

[0077] In this embodiment, multiple core blocks 23 are stacked and welded together by a first weld 5. In each core block 23, multiple core pieces 3 are stacked and integrated by riveting 24. Note that in Figure 11, the riveting 24 is conceptually shown by hatching, but does not represent a cross-section.

[0078] The core piece 3 located at the end in the stacking direction within the integrated core piece 3 does not have the starting end 5a of the first weld 5, and is equipped with an unwelded projection 15. In Figure 11, the unwelded projection 15 is shown by a dashed line.

[0079] A second welded section 9 is formed by a second weld spanning the unwelded projection 15 and the projection 15 of the additional iron core piece 7. The second welded section 9 is located on the extension of the first welded section 5 in the stacking direction. Otherwise, it is the same as in Example 1.

[0080] In this embodiment 3, the second weld 9 can be reliably formed even if the core piece 3 at the end in the lamination direction does not have the first weld 5. Furthermore, there are no restrictions on the welding direction between the first weld 5 and the second weld 9, making it easier to manufacture the laminated core 1. In addition, embodiment 3 can achieve the same effects as embodiment 1.

[0081] [Differentiation] Figure 12(A) is a schematic side view showing a laminated core piece before the formation of the second weld, relating to a modified example of Example 3, and Figure 12(B) is a schematic side view showing the laminated core after the formation of the second weld.

[0082] A modified example of Figure 12 shows that the first weld 5 comprises a full weld 19 and a partial weld 21. The partial welds 21 are provided on both sides of each full weld 19 in the circumferential direction. The partial welds 21 on both sides are located at the ends on both sides in the stacking direction of the integrated iron core piece 3. Unwelded projections 15 are continuous in the stacking direction of the partial welds 21.

[0083] The second welded section 9 is formed by a second weld that extends from the projection 15 of the end core piece 3 to the projection 15 of the additional core piece 7.

[0084] Even with this modified form, the same effects and benefits as in Example 3 can be achieved.

[0085] In the above-described embodiments 1 to 3 and modified examples, the additional core piece 7 was joined to only one end by the second weld 9. However, the additional core piece 7 may be joined to both the one end and the other end by the second weld 9. In this case, not only can the same embodiment or modified example configuration be adopted for each end, but different embodiments or modified examples can also be adopted. For example, in the modified example and embodiment 2 shown in Figure 12, it is possible to apply the configuration of the modified example, embodiment 2, or its modified example to one end and the other end, respectively. [Explanation of symbols]

[0086] 1 Laminated iron core 3 Iron core pieces 5. First Weld 5a Starting point 7. Iron core pieces for stacking 9. Second weld 15 Protrusions 17 gaps

Claims

1. Multiple iron core pieces are stacked, The stacked iron core pieces have welded portions and are joined by a first weld formed by a first weld extending between the welded portions, while the entire stacked iron core pieces are integrated. The stacking height of the integrated iron core pieces is measured, Based on the measured stacking height, additional core pieces with unwelded areas to be welded are stacked on the integrated core piece to bring the overall stacking height within a predetermined range. The first weld is formed over the entire stacking direction of the integrated iron core pieces, The end core piece in the stacking direction of the integrated core piece has the starting end of the first weld, and a second weld is formed by a second weld extending from the starting end of the first weld of the end core piece to the planned weld portion of the additional core piece, in which at least the starting end of the first weld and the planned weld portion of the additional core piece are melted and solidified, thereby joining the end core piece and the additional core piece. A method for manufacturing laminated iron cores.

2. Multiple iron core pieces are stacked, The stacked iron core pieces have welded portions and are joined by a first weld formed by a first weld extending between the welded portions, while the entire stacked iron core pieces are integrated. The stacking height of the integrated iron core pieces is measured, Based on the measured stacking height, additional core pieces with unwelded areas to be welded are stacked on the integrated core piece to bring the overall stacking height within a predetermined range. The first welded portion comprises a full-area weld formed over the entire stacking direction of the integrated core piece and a partial weld provided on a part of the stacking direction of the integrated core piece. The end core piece in the stacking direction of the integrated core piece has the starting end of the partial weld of the first weld, and a second weld is formed by a second weld extending from the starting end of the partial weld of the first weld of the end core piece to the planned welding portion of the additional core piece, thereby joining the end core piece and the additional core piece. A method for manufacturing laminated iron cores.

3. A method for manufacturing a laminated iron core according to claim 2, The end portion of the iron core piece has the starting end of the entire weld of the first weld, The second weld is formed by a second weld extending between the starting end of the partial weld and the full weld of the first weld of the end core piece and the planned weld portion of the additional core piece. A method for manufacturing laminated iron cores.

4. Multiple iron core pieces are stacked, At least a portion of the stacked iron core pieces has a welding portion, and the entire stacked iron core pieces are joined together by a first weld formed by a first weld extending between the welding portions, The stacking height of the integrated iron core pieces is measured, Based on the measured stacking height, additional core pieces with unwelded areas to be welded are stacked on the integrated core piece to bring the overall stacking height within a predetermined range. The end of the integrated core piece in the stacking direction has the starting end of the first weld, and a second weld is formed by a second weld extending from the starting end of the first weld of the end core piece to the planned welding portion of the additional core piece, thereby joining the end core piece and the additional core piece. The starting end of the first weld of the end core piece has a gap in the stacking direction between it and the planned welding portion of the stacked additional core piece, and melts and solidifies together with the planned welding portion of the additional core piece by the second welding. A method for manufacturing laminated iron cores.

5. A method for manufacturing a laminated iron core according to claim 4, The first welded portion is formed over the entire stacking direction of the integrated iron core piece, A method for manufacturing laminated iron cores.

6. A method for manufacturing a laminated iron core according to claim 3, The number of the second weld is the same as the number of the first weld. A method for manufacturing laminated iron cores.

7. Multiple iron core pieces that are stacked and joined together to form a single unit, A first welded portion is formed over the entire stacking direction of the integrated core piece, with its starting end located at least on the end of the core piece in the stacking direction, and joining at least a portion of the plurality of core pieces. The aforementioned integrated core piece is stacked with additional core pieces, A second weld extends from the additional core piece to the starting end of the first weld, and at least the starting end of the first weld and the planned weld portion of the additional core piece melt and solidify to join the additional core piece to the end core piece, A laminated iron core equipped with [a specific feature].

8. A plurality of iron core pieces that are stacked and joined together to form an integrated structure, A first welded portion whose starting end is located at least on the end of the iron core piece in the stacking direction and which joins at least a portion of the plurality of iron core pieces, The aforementioned integrated core piece is stacked with additional core pieces, A second weld extends from the aforementioned additional core piece to the starting end of the first weld and connects the additional core piece to the end core piece, Equipped with, In the second weld, at least the starting end of the first weld and the planned welding portion of the iron core piece for stacking are melted and solidified, and the height of the surface in the stacking direction decreases as it moves radially outward. Laminated iron core.

9. A method for manufacturing a laminated iron core according to any one of claims 1 to 6, The portion to be welded is a radial projection provided on the iron core piece. A method for manufacturing laminated iron cores.

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