JP2015149854A - Stator core of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a stator compact and high in performance by preventing abnormal deformation, elongation, etc., at a cut groove by devising a shape of the cut groove formed on an outer peripheral side of a wound core type laminate core, and securing circularity of the laminate core, proper arrangement of a slot part, etc.SOLUTION: A cut groove 14 provided on an outer peripheral side of a yoke part 13 comprises an arcuate bottom surface 14A which is rectangular on the whole and swells in an outer radial direction along a circumferential direction, a pair of bevels 14B which are formed at both end parts of the bottom surface 14A, and a pair of side faces 14D which extend from the pair of bevels 14B in outward radial directions to form an opening part 14C, and the side faces 14D have reversely tapered surfaces 14E formed from the side of the bottom surface 14A toward the side of the opening part 14C to narrow down the width of the cut groove 14 in the circumferential direction. Consequently, the region of the cut groove 14 has its rolling amount reduced to be as close to 0 as possible and thereby becomes a substantially unrolled region so as to eliminate straining resulting from rolling.

Description

  The present invention relates to a stator core of a rotating electrical machine, and more particularly to a laminated core type stator core suitable for a stator of an automotive alternator.

[Conventional technology]
Conventionally, various types of laminated core type stator cores have been put to practical use. In recent years, however, wound core types have been used for reasons of reduced waste materials and good material yield. In this wound core type, for example, a belt-shaped core sheet formed by punching a tooth portion and a slot portion on one side is rolled up into a circular shape one by one and laminated into a plurality of cylindrical shapes, or continuously spiral (helical) A laminated core type is obtained by winding and laminating a plurality of layers in a cylindrical shape while winding them around (see, for example, Patent Documents 1 and 2).

Furthermore, in this type of wound core, as an additional functional configuration, as shown in FIG. 8, a notch groove that is recessed from the outer peripheral surface toward the inner diameter direction over the entire axial region with respect to the yoke portion 130. 140 is provided. 8A and 8B, 130A is a region where the thickness is not rolled (thick portion), 130B is a region where the thickness is reduced by rolling (thin portion), and 130C is a boundary line between both regions.
The notch groove 140 has a semicircular shape and constitutes a component for fixing the laminated core 1. That is, for example, in order to fix and integrate the layers of the laminated core 1 in the axial direction, grooves for fitting rivets and wedges (see Patent Document 1), and grooves for welding (see Patent Document 2). ) Or a groove (see FIG. 8 of the present application) for inserting a fastening member for fixing the laminated core 1 to the housing.

[Problems of the prior art]
By the way, in rotating electrical machines with severe restrictions on mounting, such as automotive alternators, there is a demand for further downsizing and higher performance every year. Especially, the issue on the stator side is the laminated core type. The common proposition of those skilled in the art is how to reduce the size and performance of the stator core while making full use of the characteristics of the core.

  In order to meet such a proposition, the present inventor has devised a number of experiments and researches to improve the stator core in order to further reduce the size and increase the performance of the stator core. After scrutinizing the winding state, we found that the following problems were inherent.

(1) Each winding of the stator core is formed by rounding a belt-shaped core sheet in an annular shape so that the teeth and slots are on the inner peripheral side, and a notch groove provided on the outer peripheral side Has been considered to contribute to bendability in cooperation with the slot.
(2) However, when the product was observed closely, unexpectedly, abnormal deformation / elongation occurred in the notch groove, and the roundness of the laminated core (stator core) and the groove width / arrangement position of the slot part. (Pitch) and the like may be disturbed, and it has been found that this is one factor that hinders further downsizing and higher performance of the stator core.

(3) This problem will be outlined below with reference to FIG.
In order to smoothly round the core sheet 101, for example, the outer circumferential side (yoke portion 130) is pressed (rolled) in the plate thickness direction by a pair of upper and lower rolling rollers RL (usually cylinder constant pressure type) to increase the circumferential length. A method of extending the wire (a winding promotion effect is obtained) is adopted. As a result, the core sheet 101 moves from the state immediately before the notch groove 140 shown in FIG. 9A to the position of the notch groove 140 as rolling progresses as shown in FIGS. 9B and 9C. It will be rolled sequentially along the semicircular shape.
In addition, the upper figure in FIG. 9 shows the cross section along XX of the lower figure. In the lower figure, t (t0, t1, t2) is a sampling point for convenience of explanation, and a pair of rolling rollers RL In the rolling forming region, the left side of the drawing is “rolled” and the left side of the drawing is in the middle of rolling or equivalently “rolling” with the point t as a boundary. (The same applies to FIGS. 4 and 6 described later).

  The above rolling process will be supplementarily explained in the order of steps. First, as shown in FIG. 9A, in the rolling forming region up to just before the notch groove 140, the rolling area is constant and the reduction amount is constant (therefore, the predetermined elongation amount). α). Subsequently, when rolling proceeds and the rolling forming region reaches the region of the notch groove 140, the rolling area gradually decreases according to the shape of the notch groove 140. Therefore, when the point t = t0 reaches the point t = t1 shown in FIG. 9B, the pair of rolling rollers RL moves from the predetermined position (two-dot chain line position) to the solid line position (the gap between the rollers is reduced). As the amount of reduction increases, the elongation amount β is larger than the elongation amount α. Further, in the next rolling forming region, the notch groove 140 is mainly the vicinity of the groove bottom surface 141. Therefore, when the point t = t1 reaches the point t = t2 shown in FIG. 9C, the pair of rolling rollers RL. Is greatly moved from the predetermined position to the solid line position (the gap between the rollers is further reduced), and the reduction amount is further increased, whereby an elongation amount γ larger than the elongation amount β is exhibited.

  As described above, when the rolling process reaches the region of the notch groove 140, the rolling area gradually decreases and then gradually increases, and the rolling area is minimum and the pressing force is maximum near the circumferential center position (the deepest part) of the groove bottom surface 141. Therefore, in this notch groove region, the circumferential extension is extremely large (β + γ) as compared to the periphery thereof. As described above, due to the roller load concentration phenomenon due to the reduction of the rolling area, the core sheet 101 is irregularly stretched to cause distortion of the core curvature (distorted deformation), and the roundness of the inner and outer diameters of the core is deteriorated. At the same time, it was found that the groove width of the slot portions arranged on the core inner diameter side and the arrangement position (pitch) thereof vary.

(4) In addition, the notch groove 140 is an indispensable constituent element because the constituent element for fixing the laminated core can be constructed without effectively increasing the outer diameter of the core by effectively using the yoke portion 130. A means for further miniaturizing and improving the performance of the stator core while actively adopting the groove 140 is awaited.

Japanese Patent Laid-Open No. 62-244248 JP 2012-182914 A

  The present invention has been made in view of the above circumstances, and its purpose is to devise the shape of the notch groove to prevent abnormal elongation / deformation at the notch groove, An object of the present invention is to provide a stator core that contributes to miniaturization and high performance of a stator by ensuring a desired roundness of a core and proper arrangement of a slot portion.

[Means of Claim 1]
The invention according to claim 1 (a stator core of a rotating electrical machine) uses a belt-shaped core sheet made of a magnetic plate as an iron core material, and includes a tooth portion and a slot portion for winding a stator coil on the inner peripheral side. And having a basic configuration including a cylindrical laminated core having a yoke portion on the outer peripheral side. The yoke portion is provided with a notch groove having a special shape that is recessed from the outer peripheral surface toward the inner diameter direction as a component for fixing the laminated core.
The notch groove has a rectangular shape as a whole, and includes a bottom surface having an arc shape that swells in the outer diameter direction along the circumferential direction, a pair of chamfers formed at both end portions of the bottom surface, and the pair of chamfers. It consists of a pair of side surfaces that extend from the chamfering toward the outer diameter direction to form an opening, and on the side surfaces, a reverse taper surface that forms a reverse taper shape that narrows the circumferential width of the notch groove is formed. It is characterized by having.

According to the present invention having the above-described configuration, the bottom surface of the notch groove has an arc shape that swells in the outer diameter direction along the circumferential direction. In particular, by making the amount equal to or less than the predetermined elongation, it is possible to prevent abnormal elongation / deformation from occurring in the notch groove. Therefore, it is possible to provide a stator core that contributes to miniaturization and high performance of the stator by ensuring the desired roundness of the laminated core, proper arrangement of the slot portions, and the like.
In addition, since the notch groove is provided on the outer peripheral side of the yoke portion, as usual, it is possible to construct a component for fixing the laminated core without effectively increasing the outer diameter of the core by effectively using the yoke portion. It is.

Further, according to the notch groove shape of the present invention, the waste material (remaining material of the notch groove = cass) has a kind of dovetail shape with a reverse taper, so that the waste material itself has the same shape. It is possible to prevent floating from the hole (so-called dregs up). Therefore, various problems caused by the waste material being sandwiched between the core sheet, the punch, and the die can be solved, and the quality of the core sheet can be improved and the production speed (punching speed) of the core sheet can be increased.
Furthermore, since the notch groove of the present invention has a reverse tapered shape on the bottom surface side, there is an effect that the length of the bottom surface in the circumferential direction can be lengthened and the unrolled region can be expanded accordingly. As a result, the circumferential length on the outer peripheral side of the yoke portion can be increased to help ensure an effective magnetic path area.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows an automotive alternator to which a stator core according to the present invention is applied. It is a front view of the upper half part which shows a form (Example 1). For the explanation of the basic structure of the stator core and the manufacturing process thereof, (a) and (b) are a plan view and a cross-sectional view taken along the line AA of the belt-shaped core sheet obtained in the core sheet manufacturing process, (D) is the top view and BB sectional drawing of a strip | belt-shaped core sheet | seat obtained at a winding process, (e) is a perspective view of a lamination | stacking core (Example 1). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic enlarged view of a main part showing a configuration of a notch groove for use in explaining a first embodiment of a stator core to which the present invention is applied (Example 1). It serves for functional explanation of the above-mentioned stator core, and (a), (b), (c) are schematic development views around a notch groove showing the state of the order of steps in the rolling process (Example 1). FIG. 9 is a schematic enlarged view of a main part showing a configuration of a notch groove for explaining a second embodiment of a stator core to which the present invention is applied (Example 2). It serves for functional explanation of the above-mentioned stator core, and (a) and (b) are schematic development views showing the state of the order of steps in the rolling process (Example 2). FIG. 4 is a diagram for explaining a third embodiment of a stator core to which the present invention is applied, in which (a) and (b) are model diagrams for explaining a process in a core sheet winding step, and (c) is a notch groove. (Example 3) which is a typical enlarged view of the principal part which shows a structure. It is a typical enlarged view which shows the notch groove structure in the stator core of the conventional rotary electric machine (prior art). For explanation of a stator core of a conventional rotating electric machine, (a), (b), (c) are schematic development views around a notch groove showing a state of a process order in a rolling process (conventional technology). ).

  Hereinafter, the best mode for carrying out the present invention will be described in detail according to three embodiments shown in the drawings.

Each Example has shown the stator iron core of the alternator for motor vehicles as a typical example of the stator iron core to which this invention is applied. In the following description, first, the basic configuration of an automotive alternator will be outlined. Then, the feature points in each embodiment of the present invention and the basic functions of the present invention will be described in order, and finally the actions and effects for each feature point of the present invention will be summarized and listed.
In each embodiment, the same or equivalent parts are denoted by the same reference numerals, and redundant description is omitted.

[Example 1]
A first embodiment of the present invention will be described with reference to FIGS.

[Basic configuration of AC generator G]
As shown in FIG. 1A, the AC generator G includes a rotor GR attached to a rotary shaft J driven by an engine, and a pair of saddle-shaped housings H assembled by bolts (fixing members) F. And a fixed stator GS. In this stator GS, a stator core E composed of a cylindrical laminated core as shown in FIG. 1B is used as an iron core on which a stator coil (multiphase winding) D is mounted.

The stator core E is used as a part of the casing of the AC generator G by being sandwiched and fixed by a pair of housings H, and has a large number of teeth around which a stator coil D is wound. (Teeth) portions E1 and slots (grooves) E2 are provided alternately, and a cylindrical shape is provided with a yoke (junction) portion E3 that annularly connects each tooth portion E1 and slot portion E2 at a predetermined pitch on the outer peripheral side. It is composed of a laminated core 1. The annular yoke portion E3 is a non-winding portion around which the stator coil D is not wound, and a plurality of notched grooves E4, which will be described in detail later, are provided in the circumferential direction on the outer peripheral side of the yoke portion E3. In the embodiment, four are arranged equally.
The notch E4 is a component used for fixing the laminated core 1 and is used for inserting the assembly bolt F in this embodiment. Is formed over.

  As shown in FIG. 2, the laminated core 1 uses a strip-shaped core sheet 10 made of a magnetic plate 100 such as a steel plate as an iron core material. This core sheet 10 is produced, for example, as a pair (two sheets) of strip-shaped core sheets by punching out a wide elongated magnetic plate so that the teeth and slots are alternately arranged, Alternatively, it is produced as a single band-shaped core sheet by punching from a narrow band-shaped magnetic plate so that teeth and slots are alternately arranged on one side thereof.

  As shown in FIGS. 2A and 2B, the strip-shaped core sheet 10 includes a tooth portion 11 (E1) and a slot portion 12 (E2) for winding the stator coil D on one side in the length direction. ) And a yoke portion 13 (E3) for connecting the teeth portion 11 and the slot portion 12 at a predetermined pitch on the other side in the length direction, and further on the outer peripheral side of the yoke portion 13 Is provided with a notch groove 14 (E4).

  Then, as shown in FIGS. 2C and 2D, the core sheet 10 is formed in an axial direction while being bent in an annular shape so that the yoke portion 13 is on the outer peripheral side (while being spirally wound). By winding and laminating over a plurality of layers, as shown in FIG. 2E, a cylindrical laminated core 1 (E) is obtained.

  Thus, as shown in FIG. 2D, the yoke portion 13 of the core sheet 10 has a thick portion 13A having the same thickness as the tooth portion 11 on the inner peripheral side, and the outer peripheral side is formed on the outer peripheral side. A tapered thin portion 13B is formed in which the plate thickness gradually decreases from the thick portion 13A toward the outer diameter direction. The thin wall portion 13B is formed by plastic deformation in the “process of winding the laminated core 1 into a cylindrical shape”, and is substantially wound by thinning the outer peripheral side of the core sheet 10. The peripheral length is lengthened, and the core sheet 10 is easily wound up in a spiral shape.

  Here, “the process of forming the laminated core 1 in a cylindrical shape” means a process from the stage before the core sheet 10 is spirally wound (pre-process) until the core sheet 10 is further wound. As a specific method of forming the thin portion 13B in the process, there are the following two methods. The first method is a method of winding the core sheet 10 in a spiral shape, for example, including a rolling roller as a roller means for sandwiching the core sheet 10, and simultaneously winding the core sheet 10 in a spiral shape while forming the thin portion 13B. A 2nd method is the method of rolling and forming the thin part 13B with a press, for example as a pre-process which winds around the core sheet 10 in the step of the strip | belt-shaped core sheet 10 shown to Fig.2 (a). is there. The first method is exclusively used, and in this embodiment, the first method will be used and described.

[Features of laminated core 1]
The feature of the present invention resides in that a notch groove 14 provided as a component for fixing the laminated core 1 on the outer peripheral side of the laminated core 1 (yoke portion 13) has a special shape.
In the present embodiment, a notch groove 14 having a shape as shown in FIG. 3 is provided as the notch groove 14.

In FIG. 3, the notch groove 14 has the following characteristics.
(1) The notch groove 14 is formed in the yoke portion 13 so as to be recessed from the outer peripheral surface toward the inner diameter direction, and the assembly bolt F can be inserted in a loosely fitted state as a whole. The rectangular shape has a width larger than the diameter of the assembly bolt F.
(2) The rectangular cutout groove 14 includes a bottom surface 14A having an arc shape that swells in the outer diameter direction along the circumferential direction, and a pair of chamfers (R surface) 14B formed at both ends of the bottom surface 14A. , And a pair of side surfaces 14D extending from the pair of chamfers 14B in the outer diameter direction to form an opening 14C.
Note that the bottom surface 14A has a substantially linear shape instead of an arc shape in FIG. 2A, and may be formed in an arc shape in FIG. 2C. .
(3) In the cutout groove 14, the bottom surface 14A located at the deepest portion extends long in the circumferential direction along the boundary region (boundary line 13C) between the thick portion 13A and the thin portion 13B.
(4) Each side surface 14D of the notch groove 14 is formed with an inverted taper shape (inverted trapezoidal shape) that narrows the circumferential width of the notch groove 14 from the bottom surface 14A side toward the opening 14C side. A reverse tapered surface 14E is provided. In particular, in the present embodiment, in each side surface 14D, the entire region from the bottom surface 14A to the opening 14C is formed by a linear reverse tapered surface 14E. That is, the side surface 14D = reverse tapered surface 14E.

[Effect of Example 1]
According to the above configuration, the stator core E has the following operational effects.
(A) Since the notch groove 14 is provided on the outer peripheral side of the yoke portion 13 as in the configuration (1), the laminated core 1 is effectively used as before and the core outer diameter is not increased by using the yoke portion 13 effectively. A fixing component can be constructed.

(B) As in the above configuration (4), the notch groove 14 has an inverted trapezoidal shape in which the bottom surface 14A side is wide, so that the notch groove 14 can be formed with good punching.
In other words, as before, when the groove shape is made semi-circular, the waste material (remaining material of the notch groove = “cass”) also has the same shape, but the so-called residue rise that rises from the die hole of the punching die. It is easy to generate. As is well known, this “slip-up” phenomenon causes the “scum” discharged into the die hole to be lifted by being sucked by the negative pressure generated by releasing the punch inserted into the die hole at a high speed. As a result, the “cass” is caught between the core sheet 10, the punch and the die. When such a situation occurs, a dent is generated in the core sheet 10, resulting in a decrease in quality (decrease in yield), and may cause damage to punches and dies. There was a tendency to increase the production speed (punching speed) of the core sheet 10.
According to the groove shape of this embodiment, the “cass” has a dovetail shape and the die hole also has the same shape. Therefore, this shape effect makes it easy for the “cass” to be caught on the inner wall surface of the die hole. (Friction with the wall surface is increased), so that the “slip-up” phenomenon can be suppressed. Therefore, it is possible to prevent the “cass” from being caught between the core sheet 10 and the punch and the die, and greatly contribute to the improvement of the quality of the core sheet 10 and the increase in the production speed (punching speed) of the core sheet 10. it can.

(C) Furthermore, since a chamfer 14B having no corner (pin angle) is applied to a portion connecting the bottom surface 14A and the reverse tapered surface 14E, a crack is formed in a corner portion of the notch groove 14 when winding in an annular shape. It can be prevented from occurring.

(D) As in the above configurations (2) and (3), the notch groove 14 has a generally inversely tapered rectangular shape as a whole, and serves as the bottom surface of the deepest portion in the outer radial direction along the circumferential direction. Since the bottom surface 14A has an arcuate shape that swells, all the regions of the notch groove 14 can be made as close as possible to the non-rolled region so as to be substantially equal to or less than a predetermined elongation.

The effect will be supplementarily described below with reference to FIG. 4 showing the order of steps in the rolling process of the core sheet 10.
When the core sheet 10 is rolled into an annular shape, the outer peripheral side of the yoke portion 13 is rolled with a predetermined pressure in the plate thickness direction by a pair of upper and lower rolling rollers RL (for example, a cylinder constant pressure type). As a result, the core sheet 10 is moved from the state immediately before the notch groove 14 shown in FIG. 4A to the position of the notch groove 14 as rolling progresses as shown in FIGS. 4B and 4C. It will be rolled sequentially along the rectangular shape of reverse taper.

  The rolling process will be described in detail according to the order of steps. First, as shown in FIG. 4A, in the rolling forming region up to just before the notch groove 14, the rolling area is constant and the reduction amount is constant (therefore, the predetermined elongation amount α). It is. In the subsequent rolling, the rolling forming region reaches the region of the notch groove 14, but the notch groove 14 has a reverse tapered rectangular shape. Therefore, in the vicinity of the point t = t1 in FIG. 4B immediately after reaching the region of the notch groove 14, the rolling area is slightly reduced because the reverse taper portion (side surface 14D) and the chamfer 14B portion are involved. stay. As a result, the pair of rolling rollers RL is moved slightly from the predetermined position (two-dot chain line position) to the solid line position (the gap between the rollers is reduced), and the length (elongation) is substantially increased only by slightly increasing the reduction amount. (Increase) will be small. When the point t = t1 is passed, the region being rolled substantially becomes the groove bottom surface 14A of the notched groove 14. The notch groove 14 has a bottom surface 14A located on a boundary line 13C between a thick wall portion 13A that is not rolled and a tapered thin wall portion 13B formed by rolling. Therefore, after the point t = t1, for example, as represented by the point t = t2 shown in FIG. 4C, the pair of rolling rollers RL is greatly changed from the predetermined position (two-dot chain line position) to the solid line position. Even if the gap between the rollers is minimized (gap = 0), the rolling roller RL does not substantially touch the core sheet 10 and the core sheet 10 is not rolled at all (no material reduction). Amount = elongation = 0.

Thus, since all the regions of the notch groove 14 can be made as close as possible to the non-rolling region so as to be substantially equal to or less than the predetermined elongation amount, abnormal elongation or deformation at the notch groove 14 is prevented. It can be prevented from occurring.
Therefore, it is possible to provide the stator core E that contributes to the miniaturization and high performance of the stator GS by ensuring the desired roundness of the laminated core 1 and the appropriate arrangement of the slot portions 12.

(E) Since the notch groove 14 has an inverted trapezoidal shape in which the bottom surface 14A side is wide, there is an effect that the circumferential length of the bottom surface 14A can be lengthened and the unrolled region can be expanded accordingly. Since the opening 14C side is narrowed, there is an effect that the substantial circumferential direction length on the outer peripheral side of the yoke portion 13 can be lengthened to help ensure the effective magnetic path area.

[Example 2]
Next, a second embodiment of a stator core E to which the present invention is applied will be described with reference to FIGS.

[Features of Example 2]
In the first embodiment described above, the shape of the notch groove 14 is an inverted trapezoidal rectangular shape in which the side surface 14D is formed by the reverse tapered surface 14E over the entire region. The groove shape is devised so as to further increase the effective magnetic path area, and the shape of the notch groove 14 is an odd combination of the inverted trapezoidal shape on the bottom surface 14A side and the semicircular circular shape on the opening 14C side. It has a rectangular shape (cup shape).

  In FIG. 5, the notch groove 14 is for inserting an assembly bolt F that is a fixing member for attaching the laminated core 1 as in the first embodiment, and has an inverted trapezoidal shape and an opening on the bottom surface 14A side as a whole. It has a cup shape combined with a semi-circular shape on the part 14C side, the circumferential length of the bottom surface 14A is short, and the circumferential length of the opening 14C is long.

Although the bottom surface 14A of the notch groove 14 has a short circumferential length, the bottom surface 14A has an arc shape that swells in the outer diameter direction along the circumferential direction, as in the first embodiment, and has a thick portion 13A and a thin portion 13B. Is located on the boundary line 13C.
Further, side surfaces 14D are formed on both end sides of the bottom surface 14A via chamfers 14B. The side surface 14D has a reverse tapered surface 14E having an inverted trapezoidal shape formed on the bottom surface 14A side, and the reverse tapered surface. It is formed of an opening surface 14F that is formed wider on the outer diameter side than the surface 14E and forms a semi-circular opening 14C.
The opening surface 14F has an arc surface having an inner diameter slightly larger than the outer diameter of the assembly bolt F. Therefore, the assembly bolt F can be inserted into the notch groove 14 in a loosely fitted state.

[Effect of Example 2]
According to the present embodiment having the above-described configuration, the following operational effects can be obtained.
(A) The bottom surface 14A of the notch groove 14 has an arc shape that swells in the outer diameter direction along the circumferential direction, and is not rolled during rolling by the rolling roller RL as shown in FIG. 6 (b). Since the bottom surface 14A is located on the boundary line 13C between the thick portion 13A with the plate thickness and the thin portion 13B formed by rolling, the rolling roller RL does not touch the bottom surface 14A ( Not rolled).
Therefore, since the area | region of the bottom face part of the notch groove 14 can be made into a non-rolling area | region, it can prevent that abnormal elongation, a deformation | transformation, etc. arise in the notch groove 14 like Example 1. FIG.

Here, this effect will be supplementarily described with reference to FIG. 6 showing the rolling process in the notch groove 14 region.
In FIG. 6 (a), for example, the rolling forming region from the point t = t0 to t = t1 includes the vicinity of the opening surface 14F that forms the semi-notch circular opening 14C. Due to the circular shape, the circumferential width is small and a relatively large area can be secured as a whole. Therefore, the substantial elongation (elongation increase) in this portion can be suppressed to the elongation amount β or less shown in FIG. In the subsequent rolling, as shown in FIG. 6B, the notch groove 14 becomes the groove bottom surface 14A in particular. The notch groove 14 is illustrated at a point t = t2 because the bottom surface 14A is located on the boundary line 13C between the thick portion 13A that is not rolled and the tapered thin portion 13B formed by rolling. As shown, even when the pair of rolling rollers RL is significantly moved from the predetermined position (two-dot chain line position) to the solid line position and the gap between the rollers is minimized (gap = 0), the rolling roller RL is substantially attached to the core sheet 10. The core sheet 10 is not rolled (there is no material reduction), and the thickness reduction amount = elongation amount = 0.
Thus, similarly to Example 1, the region of the notch groove 14 can be made as close as possible to the non-rolled region so as to be substantially equal to or less than the predetermined elongation.

(B) The notch groove 14 has an inverted trapezoidal shape with a small area on the bottom surface 14A side, and a semi-notch circular shape with a large area on the opening 14C side. Therefore, in FIG. 5, as apparent from the comparison with the notch groove of Example 1 indicated by the phantom line, a surplus portion (hatched portion) formed by the semi-notched circular portion and the inverted trapezoidal portion having a reduced area. ) Can be utilized as the magnetic path area, and the effective magnetic path area of the yoke portion 13 can be secured larger than that of the first embodiment.

[Example 3]
Next, a third embodiment of a stator core E to which the present invention is applied will be described with reference to FIG.

  In the present embodiment, the position of the notch groove 14 is specified by skillfully utilizing the plastic deformation mechanism in the manufacturing process. In addition, as the groove shape of the notch groove 14, any shape detailed in both the above-described first and second embodiments can be adopted, but in this embodiment, the shape of the first embodiment is adopted. An aspect is demonstrated.

The wound core type stator core E to be used in the present invention has a structure in which the basic process is a manufacturing process as shown in FIG. 2 described in detail in the first embodiment, in particular, a core sheet manufacturing process and a winding process. is there.
That is, as a basic process, as shown in FIGS. 2A and 2B, a band-shaped core sheet 10 having a tooth portion 11, a slot portion 12, a yoke portion 13, and a notch groove 14 is produced from the magnetic plate 100. As shown in FIGS. 2C and 2D, while the core sheet 10 is rolled around the core sheet 10 while forming a taper-shaped thin portion 13B, as shown in FIGS. And a winding step of forming an annular shape so as to be on the side.

[Features of Example 3]
The feature of this embodiment is that the arrangement of the notch grooves 14 is set to a special relationship as follows in consideration of the plastic deformation phenomenon of the core sheet 10 that occurs in the winding process.

  That is, considering the plastic deformation phenomenon of the core sheet 10, in the winding process, the core sheet 10 is generally plastically deformed according to a deformation model as shown in FIG. In FIG. 7, by bending the core sheet 10 from the straight state shown in FIG. 7 (a) by applying a bending moment M as indicated by the arrow, the plastic sheet is stretched toward the outer periphery as shown in FIG. 7 (b). A deformation phenomenon occurs, and a plastic deformation phenomenon that tries to compress on the inner peripheral side occurs.

As described above, when the plastic deformation regions generated on the inner peripheral side and the outer peripheral side of the core sheet 10 are referred to as a compression side deformation region and a tension side deformation region, respectively, there is a region that forms a boundary between the two regions and neither compresses nor stretches. Exists. This region is a portion indicated by a one-dot chain line, and this is called a neutral line 10X.
As shown in FIG. 7C, the notch groove 14 of the present embodiment is located near the neutral line 10X (on the neutral line 10X or on the outer diameter side of the neutral line 10X) with respect to the bottom surface 14A of the notch groove 14. The feature is to do.

[Effect of Example 3]
According to the said structure, in the winding process of the core sheet 10, as shown in FIG.7 (c), the notch groove 14 and its peripheral part transfer to the tension side deformation state so that the opening part 14C may expand more. Nevertheless, since the bottom surface 14A is located near the neutral line 10X, it is not affected at all.
Therefore, it is possible to prevent the cutout groove 14 from being plastically deformed on the bottom surface 14A side in the winding process as much as possible.
Note that if the position of the bottom surface 14A of the notch groove 14 is set to the inner diameter side from the neutral line 10X, the bottom surface 14A side is positioned in the compression side deformation region, so that compression strain may occur on the bottom surface 14A side in the winding step. There is.

[Modification]
Although the present invention has been described in detail with reference to three embodiments, various modifications can be made without departing from the spirit of the present invention, and modifications thereof will be exemplified.

(1) In each example, the core sheet 10 is provided with a tapered thin portion 13B whose upper and lower surfaces are tapered over the entire circumference as a thin portion on the outer peripheral side of the yoke portion 13. It is good also as a single-sided taper thin part which makes only one side of this into a taper surface. The tapered surface is not limited to a linear shape, and may be a concave shape or a convex shape having an appropriate curvature.
However, the specifications on the product side, for example, the diameter (curvature) of the laminated core 1, the radial width of the core sheet 10, and the conditions on the manufacturing side, for example, bending means, etc., are substantially the same. Of course, the present invention can also be applied to a stator core E that is bent in an annular shape with a plate thickness (without providing a special thin wall portion) to prevent abnormal deformation in the vicinity of the notch groove 14. .

(2) Moreover, in each Example, as represented by Example 1, as a wound core type laminated core, a belt-like core sheet 10 is continuously wound in a spiral shape (helical) while being cylindrical. The laminated core 1 formed by winding and laminating over a plurality of layers is illustrated as an example, but a cylindrical wound iron core of a type in which an annular plate that is rolled up one by one from a band-shaped core sheet 10 is produced and laminated into a plurality of sheets. It can be similarly applied to.

(3) Moreover, in each Example, the shape of the notch groove 14 is showing the rectangular shape as a whole, and the bottom face 14A which makes | forms the circular arc shape swelled in the outer-diameter direction along the circumferential direction, and at least side surface 14D It is important that a part has a reverse taper surface 14E that narrows the circumferential width of the notch groove 14 from the bottom surface 14A side toward the opening 14C side. The reverse taper surface 14E is linear. Without being limited, it may be a concave shape or a convex shape having an appropriate curvature.
Further, the shape of the chamfer 14B connecting the bottom surface 14A and the reverse tapered surface 14E is not limited to the illustrated R surface 14B, and may be a linear so-called C surface.

(4) In the above embodiment, the cutout groove 14 to which the present invention is applied is represented by the component for inserting the assembly bolt F forming the fixing member for attaching the laminated core 1. In order to fix and integrate the layers in the axial direction, a groove for fitting a fixing member such as a rivet or a wedge (see Patent Document 1) and a groove for welding (see Patent Document 2) By applying the present invention, the same effects can be achieved. Needless to say, the number of notches 14 and the arrangement interval can be selected according to the purpose.

(5) Moreover, although the above embodiment demonstrated the case where this invention was applied to the stator iron core of the alternating current generator (alternator) for motor vehicles, it is not restricted to this, The wound iron core which consists of a magnetic board as a core material The present invention can be applied to a rotary electric machine having a stator iron core of a type, for example, a high voltage drive motor, and can provide the same operational effects.

  The features and effects of the present invention that have been described in detail above will be summarized as follows according to the means described as the dependent claims (claims 2 to 5) in the claims.

(Feature 1 = Means of claim 2)
In the stator core E of the rotating electrical machine (AC generator G) according to claim 1, the yoke portion 13 has a thick portion 13A having an inner peripheral side having the same plate thickness as that of the teeth portion 11, The outer peripheral side of the thick portion 13A forms a tapered thin portion 13B in which the plate thickness gradually decreases toward the outer diameter direction, and the bottom surface 14A of the notch groove 14 is formed between the thick portion 13A and the thin portion 13B. (Examples 1 and 2) characterized by extending in the circumferential direction along the boundary region.
According to the above means, the bottom surface 14A of the notch groove 14 extends in the circumferential direction along the boundary region of the rolled portion (thin wall portion 13B). The entire region (corresponding to the region) can be a non-rolling region where the reduction amount = 0, and the desired roundness of the laminated core 1 is combined with the winding promoting effect by the tapered thin portion 13B. Further, it is possible to further contribute to ensuring proper arrangement of the slot portion 12 and the like.

(Feature point 2 = Means of claim 3)
In the stator core E of the rotating electrical machine (AC generator G) according to claim 1 or 2, the notch groove 14 has a reverse taper shape in which the side surface 14D has a reverse taper shape over the entire region from the bottom surface 14A to the opening 14C. It is characterized by being formed by the surface 14E (Example 1).
According to the above means, it is possible to realize a non-rolling region where the reduction amount = 0 substantially over the entire area of the notch groove 14.

(Feature point 3 = Means of claim 4)
In the stator core E of the rotating electrical machine (AC generator G) according to claim 1 or 2, the notch groove 14 is for inserting a fixing member (assembly bolt F) for attaching the laminated core 1. The side surface 14D is composed of an inversely tapered tapered surface 14E formed on the bottom surface 14A side and a semi-circular circular opening surface 14F formed to expand to the outer diameter side from the tapered surface 14E. A fixing member (assembly bolt F) is fitted into the opening surface 14F (Example 2).
According to the above means, the cutout groove 14 can be configured as an inverted trapezoidal shape with a small area on the bottom surface 14A side and a semicircular shape with a large area on the opening 14C side. F) Since the surplus portion can be secured on the side surface 14D side of the cutout groove 14 while keeping the minimum size matched with the outer shape, the effective magnetic path area of the yoke portion 13 is further increased. be able to.

(Feature point 4 = Means of claim 5)
In the stator core E of the rotating electrical machine (AC generator G) according to any one of claims 1 to 4, when the core sheet 10 is formed in an annular shape, the inner peripheral side and the outer periphery of the core sheet 10 are formed. The plastic deformation regions generated on the side are referred to as the compression side deformation region and the tension side deformation region, respectively. When the region that forms the boundary between the two regions and does not compress or stretch is referred to as the neutral line 10X, the bottom surface 14A of the notch groove 14 Is positioned on the outer diameter side including the neutral wire 10X (Example 3).
According to the above means, it is possible to prevent distortion from occurring in the vicinity of the bottom surface 14A of the notch groove 14 even with respect to the plastic deformation phenomenon (not related to rolling) in the winding process of the core sheet 10, and the laminated core It is possible to further contribute to ensuring the desired roundness of 1 and proper arrangement of the slot portion 12.

  DESCRIPTION OF SYMBOLS 1 ... Laminated core, 10 ... Core sheet, 11 ... Teeth part, 12 ... Slot part, 13 ... Yoke part, 14 ... Notch groove, 14A ... Bottom face, 14B ... Chamfering, 14C ... Opening part, 14D ... Side face, 14E ... Tapered surface, 100: magnetic plate, E: stator core, G: automotive alternator (rotary electric machine).

Claims (5)

A belt-shaped core sheet (10) made of a magnetic plate (100) is used as an iron core material, and the core sheet (10) is formed in an annular shape and laminated in the axial direction, thereby forming a cylindrical shape as a whole. The laminated core (1) is configured,
The core sheet (10) alternately has teeth (11) and slots (12) for winding the stator coil (D) on the inner peripheral side, and the teeth (11) on the outer peripheral side. And in the stator core (E) of the rotating electrical machine (G) having a yoke part (13) connecting the slot parts (12) at a predetermined pitch,
The yoke portion (13) includes a notch groove (14) that is recessed from the outer peripheral surface toward the inner diameter direction as a component used for fixing the laminated core (1).
The notch groove (14) has a rectangular shape as a whole, and is formed on the bottom surface (14A) having an arc shape that swells in the outer diameter direction along the circumferential direction, and at both end portions of the bottom surface (14A). A pair of chamfers (14B) and a pair of side surfaces (14D) extending from the pair of chamfers (14B) in the outer diameter direction to form an opening (14C),
The side surface (14D) has a reverse taper surface (14E) that forms a reverse taper shape that narrows the circumferential width of the notch groove (14) from the bottom surface (14A) side toward the opening (14C) side. ) Is formed, the stator core (E) of the rotating electrical machine (G). In the stator core (E) of the rotating electrical machine (G) according to claim 1,
The yoke portion (13) has a thick portion (13A) whose inner peripheral side has the same thickness as that of the teeth portion (11), and the outer peripheral side of the thick portion (13A) has an outer diameter. It has a tapered thin part (13B) whose thickness gradually decreases toward the direction,
A rotating electric machine characterized in that a bottom surface (14A) of the notch groove (14) extends in a circumferential direction along a boundary region between the thick portion (13A) and the thin portion (13B). (G) Stator core (E). In the stator core (E) of the rotating electrical machine (G) according to claim 1 or 2,
The notch groove (14) is formed such that the side surface (14D) has a reverse taper surface (14E) having a reverse taper shape over the entire region from the bottom surface (14A) to the opening (14C). The stator iron core (E) of the rotating electrical machine (G) characterized. In the stator core (E) of the rotating electrical machine (G) according to claim 1 or 2,
The notch groove (14) is for inserting the fixing member (F) for attaching the laminated core (1),
The side surface (14A) has a reverse tapered surface (14E) formed on the bottom surface (14A) side, and a semi-circular circular shape formed by expanding from the reverse tapered surface (14E) to the outer diameter side. It consists of an opening surface (14F),
The stator core (E) of the rotating electrical machine (G), wherein the fixing member (F) is fitted to the opening surface (14F). In the stator core (E) of the rotating electrical machine (G) according to any one of claims 1 to 4,
The plastic deformation regions generated on the inner peripheral side and the outer peripheral side of the core sheet (10) when the core sheet (10) is formed in an annular shape are called a compression side deformation region and a tension side deformation region, respectively. When we call the neutral line (10X) the region that borders the two regions and does not compress or stretch,
The stator core (E) of the rotating electrical machine (G), wherein the bottom surface (14A) of the notch groove (14) is positioned on the outer diameter side including the neutral line (10X).

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