Patent Description:
There is known a stator manufacturing method and stator manufacturing apparatus for manufacturing a stator including a stator core and coils (see PTL <NUM>, for example). In the method and apparatus described in PTL <NUM>, the lead wire portions of coils formed by flat conductors are bent, the lead wire portions projecting in the axial direction from the end surface of the stator core. The lead wire portion of each coil is connected by welding or the like to the lead wire portion of another coil apart from the coil by a predetermined distance in the circumferential direction.

<CIT> discloses a method for manufacturing a stator in which a bus bar comprises a joining part joined to a terminal of another coil and a spanning part formed between the joining part and a winding part. <CIT> discloses a manufacturing method for a stator in which coils are connected via joint portions. <CIT> discloses a stator including a cage coil. <CIT> discloses a method of connecting a bus bar to the coil of a stator, involving superposing the front-end of the bus bar on top of the outer peripheral side edge portion of the coil.

PTL <NUM> discloses a stator manufacturing method according to the preamble of claim <NUM> and a stator according to the preamble of claim <NUM>.

However, in the above method and apparatus described in PTL <NUM>, the ends of the lead wire portions of the coils are oriented in the axial direction of the stator. Accordingly, the lead wire portions of the stator coils are connected to each other in positions away from the end surface of the stator core and the dimension in the axial direction of the entire stator becomes large.

In contrast, when the lead wire portions of the coils are connected to each other in the state in which both parts are oriented in the radial direction, the dimension in the axial direction of the entire stator can be reduced (see PTL <NUM>, for example). However, when the lead wire portions on the inner diameter side are bent (bent flatwise) radially outward across the coil end portions after the coils are attached to the stator core, it is necessary to dispose a bending fulcrum jig between the vertex portions of the coil end portions and the bent portions obtained by bending the lead wire portions and bend the coils at the positions more distant in the axial direction from the stator core than vertex portions. Accordingly, even after the bending fulcrum jig is removed (that is, after flatwise bending), the space for the dimension of the jig remains between the vertex portions of the coil end portions and the bent portions obtained by bending of the lead wire portions, thereby increasing the dimension in the axial direction of the entire stator by the dimension of the jig.

An object of the disclosure is to provide a stator manufacturing method and a stator capable of reducing the dimension in the axial direction of the stator.

According to an aspect of the disclosure, there is provided a stator manufacturing method according to claim <NUM>.

According to another aspect of the disclosure, there is provided a stator according to claim <NUM>.

According to an aspect of the disclosure, a stator manufacturing method capable of reducing the dimension in the axial direction of the stator can be obtained. In addition, according to another aspect of the disclosure, a stator having a reduced dimension in the axial direction can be obtained.

Embodiments will be described below with reference to the drawings.

<FIG> is the perspective view illustrating the stator manufactured by the stator manufacturing method and the stator manufacturing apparatus according to the embodiment of the invention. <FIG> illustrates an example of the procedure for bending the lead wire portion of the concentrically wound coil before manufacturing the stator by the stator manufacturing method and the stator manufacturing apparatus according to the embodiment. <FIG> illustrate the positional relationship between two concentrically wound coils adjacent to each other in the circumferential direction in the embodiment. <FIG> is a view seen from the center of the axis and <FIG> is a view seen from the axial direction. In addition, <FIG> illustrates an example of the procedure for forming a coil assembly shaped like an annular cage using a plurality of concentrically wound coils in the embodiment.

A stator manufacturing apparatus <NUM> according to the embodiment manufactures a stator <NUM> that is a stator used for a rotary electric machine such as, for example, a three-phase AC motor. The stator <NUM> is a member, disposed radially outward of a rotor with a predetermined air gap, that generates a magnetic field for rotating the rotor by energization. The stator <NUM> includes a stator core <NUM> and a stator coil <NUM>.

The stator core <NUM> is a member formed in a hollow cylinder. A space (inner diameter side space) <NUM> for accommodating the rotor is formed on the inner diameter side of the stator core <NUM>. The stator core <NUM> may be formed by laminating a plurality of insulation-coated electromagnetic steel plates in the axial direction. In addition, the radially outward end surface of the stator core <NUM> may be provided with a cylindrical yoke made of a material obtained by compression-molding insulation-coated soft magnetic powder.

The stator core <NUM> includes a back yoke <NUM> formed in an annular ring and teeth <NUM> extending radially inward (toward the axial center) from the radially inward end surface of the back yoke <NUM>. The plurality of (for example, <NUM>) teeth <NUM> are provided in the back yoke <NUM> at regular intervals in the circumferential direction. A slot <NUM> for holding the stator coil <NUM> is formed between the two teeth <NUM> adjacent to each other in the circumferential direction.

The stator core <NUM> is provided with ear portions <NUM> used to fix the stator <NUM> to the motor case. The ear portion <NUM> is formed in a mount projecting radially outward from the radially outward end surface (outer peripheral surface) of the body of the stator core <NUM> (specifically, the back yoke <NUM>). The plurality of (for example, <NUM>) ear portions <NUM> are provided distantly from each other in the circumferential direction. The ear portion <NUM> is provided with a through hole <NUM> penetrating through the ear portions <NUM> in the axial direction. The stator <NUM> is fixed to the motor case by tightening the bolts penetrating through the through holes <NUM> of the ear portions <NUM> using nuts.

In addition, the stator coil <NUM> is formed by a flat conductive wire having a quadrilateral (specifically, rectangular) cross section. This flat conductive wire is made of metal having a high conductivity, such as, for example, copper or aluminum. The corners of the rectangular cross section of the flat conductive wire may be rounded. The plurality of (for example, <NUM>) stator coils <NUM> are provided for the stator core <NUM> in the circumferential direction.

Each of the stator coils <NUM> is a concentrically wound coil (cassette coil) formed by winding a flat conductive wire a predetermined number of (for example, five) turns and bending the wound flat conductive wire. The stator coil <NUM> is referred to below as the concentrically wound coil <NUM>. The concentrically wound coil <NUM> is formed by winding one straight flat conductive wire for a predetermined number of turns while shaping the conductive wire in an ellipse using a winding formation apparatus and then bending the wound conductive wire in a substantially hexagon or substantially an octagon using a shaping apparatus.

The concentrically wound coil <NUM> has slot accommodation portions <NUM> and <NUM> and coil end portions <NUM> and <NUM>. The slot accommodation portions <NUM> and <NUM> are accommodated in the slots <NUM> of the stator core <NUM> and extend substantially straight by penetrating through the slots <NUM> in the axial direction. In the single concentrically wound coil <NUM>, the slot accommodation portion <NUM> and the slot accommodation portion <NUM> are accommodated in the different slots <NUM> apart from each other by a predetermined distance in the circumferential direction of the stator core <NUM>. The coil end portions <NUM> and <NUM> are curved portions projecting outward in the axial direction from the end surface in the axial direction of the stator core <NUM> and connecting the two slot accommodation portions <NUM> and <NUM> apart from each other in the circumferential direction.

The concentrically wound coil <NUM> is configured so that a plurality of flat conductive wires are laminated in the short-side direction of the cross section of the flat conductive wire and a predetermined space is formed in the lamination direction in which the flat conductive wires are laminated between adjacent flat conductive wires. The concentrically wound coil <NUM> is formed to have a trapezoid cross section so that the separation distance (interval) between the two slot accommodation portions <NUM> and <NUM> changes depending on the position in the lamination direction. The trapezoid cross section is formed so that the slot accommodation portions <NUM> and <NUM> of the concentrically wound coil <NUM> are appropriately accommodated in the slots <NUM>. The concentrically wound coils <NUM> are assembled to the stator core <NUM> so that the lamination direction of the flat conductive wires matches the radial direction orthogonal to the axial direction of the stator core <NUM>.

The coil end portions <NUM> and <NUM> of the concentrically wound coil <NUM> are formed in a plurality of different non-linear shapes. Specifically, the coil end portions <NUM> and <NUM> are formed in, for example, three non-linear shapes: crank formation like a crank bent in steps toward the radial direction of the stator core <NUM>, arc formation like an arc curved along the arc of the annular stator core <NUM>, and edgewise formation like a knee bent in the longitudinal direction of the cross section of a flat conductive wire. Crank formation is bending performed for a lane change between the flat conductive wires in the lamination direction of the flat conductive wires. Arc formation is bending performed to efficiently accommodate the concentrically wound coils <NUM> in the slots <NUM>. In addition, edgewise formation is bending performed to efficiently dispose the plurality of the concentrically wound coils <NUM>.

The concentrically wound coil <NUM> has lead wire portions <NUM> and <NUM> at both ends of the flat conductive wire. The lead wire portion <NUM> is connected to the end of the slot accommodation portion <NUM> to be accommodated in the slot <NUM>. The lead wire portion <NUM> is connected to the end of the slot accommodation portion <NUM> to be accommodated in the slot <NUM>. The lead wire portions <NUM> and <NUM> project in the axial direction from the end surface in the axial direction of the stator core <NUM> when the slot accommodation portions <NUM> and <NUM> are accommodated in the slots <NUM> of the stator core <NUM>. It is assumed that the lead wire portions <NUM> and <NUM> project in the axial direction on a coil end portion <NUM> side.

The lead wire portion <NUM> is an end portion positioned on the inner diameter side in the concentrically wound coil <NUM> formed by winding a flat conductive wire for a predetermined number of turns. The lead wire portion <NUM> is an end portion positioned on the outer diameter side in the concentrically wound coil <NUM>. The lead wire portion <NUM> is referred to below as the inner diameter side lead wire portion <NUM> and the lead wire portion <NUM> is referred to below as the outer diameter side lead wire portion <NUM> as appropriate. Immediately after the concentrically wound coil <NUM> is bent in substantially a hexagon or substantially an octagon by the shaping apparatus, the lead wire portions <NUM> and <NUM> are formed so as to extend substantially linearly. If the concentrically wound coil <NUM> is attached to the stator core <NUM> and the slot accommodation portions <NUM> and <NUM> are accommodated in the slots <NUM> of the stator core <NUM>, the lead wire portions <NUM> and <NUM> are formed so as to extend substantially linearly in the axial direction.

After the concentrically wound coil <NUM> is bent in substantially a hexagon or substantially an octagon by the shaping apparatus, the lead wire portions <NUM> and <NUM> are crooked and bent before a coil assembly <NUM> is configured by the plurality of the concentrically wound coils <NUM> as described later. After the coil assembly <NUM> is configured and then the concentrically wound coils <NUM> are inserted into the slots <NUM> of the stator core <NUM>, the lead wire portions <NUM> and <NUM> are also crooked and bent as described later.

Specifically, before the coil assembly <NUM> is configured, as illustrated in <FIG>, the inner diameter side lead wire portion <NUM> is first bent in a circumferentially outward direction (counterclockwise direction in <FIG>) which is an edgewise direction of a flat conductive wire at a connection part 50a connecting to the slot accommodation portion <NUM>, next bent in a circumferentially inward direction (clockwise direction in <FIG>) which is the edgewise direction of the flat conductive wire at a connection part 50b positioned closer to the end than the bent portion 50a, then bent in the circumferentially outward direction (counterclockwise direction in <FIG>) which is the edgewise direction of the flat conductive wire at a part 50c positioned closer to the end than the bent portion 50b, and finally bent in the circumferentially inward direction (clockwise direction in <FIG>) which is the edgewise direction of the flat conductive wire at a portion 50d positioned closer to the end than the bent portion 50c. At this time, the bent portion 50a is bent at an angle smaller than the final desired angle with respect to the axial direction so that the inner diameter side lead wire portion <NUM> follows the circumferential direction in advance.

In addition, the outer diameter side lead wire portion <NUM> is first bent in the circumferentially outward direction (clockwise direction in <FIG>) which is the edgewise direction of the flat conductive wire in a vicinity 52a of the connection part connecting to the slot accommodation portion <NUM>, next bent in the circumferentially inward direction (counterclockwise direction in <FIG>) which is the edgewise direction of the flat conductive wire at a part 52b positioned closer to the end than the bent portion 52a, and finally bent in the radially outward direction which is the flatwise direction of the flat conductive wire at a portion 52c positioned closer to the end than the bent portion 52b.

The positions and the degrees of bending of the bent portions 50a, 50b, 50c, and 50d of the inner diameter side lead wire portion <NUM> are set so according to the final desired shape of the concentrically wound coil <NUM>. In addition, the positions and the degrees of bending of the bent portions 52a, 52b, and 52c of the outer diameter side lead wire portion <NUM> are set according to the final desired shape of the concentrically wound coil <NUM>.

When bent as described above, the inner diameter side lead wire portion <NUM> includes an extending portion 50e extending from the bent portion 50a to the bent portion 50b, an extending portion 50f extending from the bent portion 50b to the bent portion 50c, an extending portion <NUM> extending from the bent portion 50c to the bent portion 50d, and an extending portion <NUM> extending from the bent portion 50d to the end. In addition, when bent as described above, the outer diameter side lead wire portion <NUM> includes an extending portion 52d extending from the bent portion 52a to the bent portion 52b, an extending portion 52e extending from the bent portion 52b to the bent portion 52c, and an extending portion 52f extending from the bent portion 52c to the end.

If the concentrically wound coil <NUM> is attached to the stator core <NUM> and the slot accommodation portions <NUM> and <NUM> are accommodated in the slots <NUM> of the stator core <NUM>, the extending portion 50e of the inner diameter side lead wire portion <NUM> extends in the circumferentially outward direction while extending in the axial direction of the stator <NUM>. In addition, the extending portion 50f extends substantially in the axial direction of the stator <NUM>, the extending portion <NUM> extends in the circumferentially outward direction while extending in the axial direction of the stator <NUM>, and the extending portion <NUM> extends substantially in the axial direction (may be inclined slightly in the circumferential direction) of the stator <NUM>. Since the above bending is performed in the edgewise direction of the flat conductive wire, the extending portions 50e, 50f, <NUM>, and <NUM> are formed substantially concentrically after being bent as described above.

In addition, if the concentrically wound coil <NUM> is attached to the stator core <NUM> and the slot accommodation portions <NUM> and <NUM> are accommodated in the slots <NUM> of the stator core <NUM>, the extending portion 52d of the outer diameter side lead wire portion <NUM> extends in the circumferentially outward direction while extending in the axial direction of the stator <NUM>. In addition, the extending portion 52e extends substantially in the axial direction of the stator <NUM> and the extending portion 52f extends radially outward.

The plurality of concentrically wound coils <NUM> are disposed in the circumferential direction to configure the coil assembly <NUM> shaped like an annular cage. The coil assembly <NUM> is formed in an annular cage by crooking and bending the concentrically wound coils <NUM> as described above in the lead wire portions <NUM> and <NUM> and disposing the plurality of the concentrically wound coils <NUM> annularly in the circumferential direction. The coil assembly <NUM> is formed so as to achieve the following items (i) to (iii).

When the stator <NUM> is applied to, for example, a three-phase AC motor, the concentrically wound coils <NUM> constitute a U-phase coil, V-phase coil, or W-phase coil. For example, in the coil assembly <NUM>, one polarity is formed by the six concentrically wound coils <NUM> arranged in the circumferential direction including two U-phase coils, two V-phase coils, and two W-phase coils, which are the concentrically wound coils <NUM>, arranged in the circumferential direction.

The stator <NUM> also has an insulation member <NUM> for ensuring electric insulation between the stator core <NUM> and the concentrically wound coils <NUM>. The insulation member <NUM> is a slot cell that has the shape corresponding to the slot <NUM> of the stator core <NUM>, is attached to each of the slots <NUM>, and has a U-shaped cross section. The insulation member <NUM> is a thin film member made of paper or resin (such as, for example, thermoset resin or thermoplastic resin). After the coil assembly <NUM> including a predetermined number of the concentrically wound coils <NUM> is formed as illustrated in <FIG>, the insulation member <NUM> is attached to the coil assembly <NUM> by inserting the insulation member <NUM> into the slot accommodation portions <NUM> and <NUM> of the concentrically wound coils <NUM> from the outer diameter side to the inner diameter side of the slot accommodation portions <NUM> and <NUM>.

Next, the procedure for manufacturing the stator <NUM> in the embodiment will be described.

In the embodiment, the stator <NUM> is assembled by attaching the concentrically wound coils <NUM> of the coil assembly <NUM> to the stator core <NUM>, that is, by inserting the slot accommodation portions <NUM> and <NUM> of the concentrically wound coils <NUM> into the slots <NUM> of the stator core <NUM>.

In the coil assembly <NUM>, before the slot accommodation portions <NUM> and <NUM> of the concentrically wound coil <NUM> are inserted into the slots <NUM> of the stator core <NUM>, the separation distance (interval) between the two slot accommodation portions <NUM> and <NUM> of the concentrically wound coil <NUM> is smaller than after the slot accommodation portions <NUM> and <NUM> are inserted into the slots <NUM>, so the length in the axial direction (specifically, the distance between the end in the axial direction of the coil end portion <NUM> and the end in the axial direction of the coil end portion <NUM>) is larger and the outer diameter is smaller (specifically, the outer diameter is slightly smaller than the inner diameter of the teeth <NUM> of the stator core <NUM>). For convenience sake, the coil assembly <NUM> before the slot accommodation portions <NUM> and <NUM> are inserted into the slots <NUM> of the stator core <NUM> is referred to as the initial coil assembly <NUM> and the coil assembly <NUM> after the slot accommodation portions <NUM> and <NUM> are inserted into the slots <NUM> of the stator core <NUM> is referred to as the inserted coil assembly <NUM>.

In the embodiment, the initial coil assembly <NUM> and the stator core <NUM> are prepared. The initial coil assembly <NUM> includes the plurality of the concentrically wound coils <NUM> disposed annularly, each of the concentrically wound coils <NUM> having the extending portions 50e, 50f, <NUM>, and <NUM> formed substantially concentrically, and the insulation member <NUM> attached to the slot accommodation portions <NUM> and <NUM> of the concentrically wound coils <NUM>. As described above, the initial coil assembly <NUM> is configured to have an outer diameter slightly smaller than the inner diameter of the teeth <NUM> of the stator core <NUM>. First, the stator core <NUM> is assembled to the initial coil assembly <NUM> so that the initial coil assembly <NUM> is inserted into the inner diameter side space <NUM> from the axial direction of a coil end portion <NUM> side on which the lead wire portions <NUM> and <NUM> of the concentrically wound coils <NUM> are not provided. When this assembly is performed, the initial coil assembly <NUM> is disposed in the inner diameter side space <NUM> of the stator core <NUM>.

After the initial coil assembly <NUM> and the stator core <NUM> are inserted and disposed as described above, the initial coil assembly <NUM> and the stator core <NUM> are positioned in the circumferential direction, the jig is pushed against the coil end portions <NUM> and <NUM> of the concentrically wound coils <NUM> constituting the initial coil assembly <NUM> to push the coil end portions <NUM> and <NUM> radially outward. When the coil end portions <NUM> and <NUM> of the concentrically wound coils <NUM> are pushed radially outward, the slot accommodation portions <NUM> and <NUM> connected to the coil end portions <NUM> and <NUM> follow the pushed coil end portions <NUM> and <NUM> and are pulled from the inner diameter side to the outer diameter side, so the slot accommodation portions <NUM> and <NUM> are inserted into the slots <NUM>.

In the insertion process of the slot accommodation portions <NUM> and <NUM>, the concentrically wound coils <NUM> are deformed so that the distance (interval) in the circumferential direction between the slot accommodation portion <NUM> and the slot accommodation portion <NUM> is gradually increased and the distance in the axial direction between the end in the axial direction of the coil end portion <NUM> and the end in the axial direction of the coil end portion <NUM> is gradually reduced.

In this stator assembling method, the two concentrically wound coils <NUM> disposed in different positions in the circumferential direction are assembled to each other so that the flat conductive wires of the slot accommodation portions <NUM> and <NUM> are alternately arranged radially in the same slots <NUM> and, after the initial coil assembly <NUM> including a predetermined number of the concentrically wound coils <NUM> disposed annularly is formed, in the state in which the initial coil assembly <NUM> is disposed in the inner diameter side space <NUM> (formed in a hollow cylinder) of the stator core <NUM>, the slot accommodation portions <NUM> and <NUM> of the plurality of the concentrically wound coils <NUM> constituting the coil assembly <NUM> can be inserted into the slots <NUM> of the stator core <NUM> and the concentrically wound coils <NUM> constituting the coil assembly <NUM> can be assembled to the stator core <NUM>.

<FIG> illustrates the process of bending the lead wire portions <NUM> and <NUM> of the concentrically wound coils <NUM> in the stator manufacturing method and the stator manufacturing apparatus <NUM> according to the embodiment. <FIG> illustrates the preprocess jig included in the stator manufacturing apparatus <NUM> according to the embodiment and the process of bending the lead wire portions <NUM> of the concentrically wound coils <NUM> using the preprocess jig. <FIG> illustrates the post-process jig included in the stator manufacturing apparatus <NUM> according to the embodiment and the process of bending the lead wire portion <NUM> of the concentrically wound coil <NUM> using the post-process jig. <FIG> and <FIG> illustrate the states before bending.

<FIG> and <FIG> illustrate the state before bending the lead wire portions <NUM> of the concentrically wound coils <NUM> in the stator manufacturing method and the stator manufacturing apparatus <NUM> according to the embodiment. <FIG> and <FIG> illustrate the state after bending the lead wire portions <NUM> of the concentrically wound coils <NUM> using the preprocess jig in the stator manufacturing method and the stator manufacturing apparatus <NUM> according to the embodiment. <FIG> and <FIG> illustrate the state while bending the lead wire portions <NUM> of the concentrically wound coils <NUM> using the post-process jig in the stator manufacturing method and the stator manufacturing apparatus <NUM> according to the embodiment. In addition, <FIG> and <FIG> illustrate the state after bending the lead wire portions <NUM> of the concentrically wound coils <NUM> using the post-process jig in the stator manufacturing method and the stator manufacturing apparatus <NUM> according to the embodiment.

<FIG>, <FIG>, <FIG>, and <FIG> illustrate perspective views. <FIG>, <FIG>, and <FIG> are three-plane views each including a front view seen from the axial direction from which the lead wire portions <NUM> and <NUM> can be seen, a side view, and another side view. In addition, <FIG> includes a front view seen from the axial direction from which the lead wire portions <NUM> and <NUM> can be seen, a side view, and a cross sectional view taken along line III-III. <FIG> is a schematic diagram enlarging portion X in <FIG>.

<FIG> illustrates the relationship between the positions in the axial direction of the post-process jig included in the stator manufacturing apparatus <NUM> according to the embodiment and the lead wire portions <NUM> of the concentrically wound coils <NUM> bent by the post-process jig. <FIG> is a cross sectional view illustrating the stator <NUM>. In addition, <FIG> illustrates effects obtained when the lead wire portion <NUM> of the concentrically wound coil <NUM> is bent in the stator manufacturing method and the stator manufacturing apparatus <NUM> according to the embodiment.

In the embodiment, when the slot accommodation portions <NUM> and <NUM> of all the concentrically wound coils <NUM> constituting the coil assembly <NUM> shaped like an annular cage are pushed toward the outer diameter side, all the concentrically wound coils <NUM> are radially pushed from the inner diameter side to the outer diameter side, the concentrically wound coils <NUM> are attached to the stator core <NUM>, and the lead wire portions <NUM> and <NUM> (particularly, the inner diameter side lead wire portions <NUM>) of the concentrically wound coils <NUM> are bent. This bending is performed so that the inner diameter side lead wire portion <NUM> extends radially outward across the coil end portion <NUM> to connect the end of the inner diameter side lead wire portion <NUM> of one concentrically wound coil <NUM> to the end of the outer diameter side lead wire portion <NUM> of the other concentrically wound coil <NUM> of the two concentrically wound coils <NUM> disposed apart from each other in the circumferential direction by a predetermined distance.

Specifically, before the stator manufacturing apparatus <NUM> performs bending, the inner diameter side lead wire portion <NUM> is formed to have the extending portions 50e, 50f, <NUM>, and <NUM> formed substantially concentrically (<FIG>). First, the stator manufacturing apparatus <NUM> performs flatwise bending of the inner diameter side lead wire portion <NUM> using, as a fulcrum, the extending portion 50f (the portion surrounded by the dashed line in <FIG>) extending substantially in the axial direction so that the portion (specifically, the extending portions <NUM> and <NUM> and referred to below simply as "the end side portions <NUM> and <NUM>") positioned closer to the end than the extending portion 50f topples radially outward (<FIG>). Next, using the bent portion 50a (the portion surrounded by the dashed line in <FIG>) as a fulcrum, edgewise bending of the part (specifically, the extending portions 50e, 50f, <NUM>, and <NUM>, that is, the entire inner diameter side lead wire portion <NUM>) positioned closer to the end than the bent portion 50a is performed along the circumferential direction of the stator core <NUM> so as to approach the end surface in the axial direction of the stator core <NUM> (counterclockwise in <FIG>).

The stator manufacturing apparatus <NUM> has a flatwise (FW) jig <NUM> for flatwise bending of the inner diameter side lead wire portion <NUM>. The FW jig <NUM> includes a fulcrum jig <NUM> for supporting the inner diameter side lead wire portion <NUM> when performing flatwise bending of the inner diameter side lead wire portion <NUM> and a bending jig <NUM> for bending the inner diameter side lead wire portion <NUM> when performing flatwise bending of the inner diameter side lead wire portion <NUM>.

The fulcrum jig <NUM> is a member extending like a bar, has a support portion <NUM> having a U-shaped notch at its end into which one inner diameter side lead wire portion <NUM> can be fitted, and has a cutout portion <NUM> that has been cut out in the portion with which the surface of the inner diameter side lead wire portion <NUM> makes contact when flatwise bending of the inner diameter side lead wire portion <NUM> is performed. The fulcrum jig <NUM> is supported by a moving mechanism (not illustrated) movably in a radial direction of the stator <NUM>. The fulcrum jig <NUM> is movable in a radial direction along the vertex portion of the coil end portion <NUM> right above the vertex portion. The fulcrum jig <NUM> is moved from radially outward to radially inward of the stator <NUM> immediately before flatwise bending of the inner diameter side lead wire portion <NUM> is performed so that the extending portion 50f of the inner diameter side lead wire portion <NUM> is fitted into the support portion <NUM>.

In addition, the bending jig <NUM> has a depression portion <NUM> that can make contact with the surface corresponding to the longer side of the cross section of the flat conductive wire of the inner diameter side lead wire portion <NUM>. The depression portion <NUM> is configured by, for example, a rotatable roller. The bending jig <NUM> is supported by a moving mechanism (not illustrated) movably in a radial direction of the stator <NUM>. When flatwise bending of the inner diameter side lead wire portion <NUM> is performed, the bending jig <NUM> is moved from radially inward to radially outward of the stator <NUM> and pushes the inner diameter side lead wire portion <NUM> radially outward while making contact with the end side of the extending portion 50f of the inner diameter side lead wire portion <NUM> via the depression portion <NUM>.

The stator manufacturing apparatus <NUM> also has an edgewise (EW) jig <NUM> for edgewise bending of the inner diameter side lead wire portion <NUM>. The EW jig <NUM> includes a fulcrum jig <NUM> for supporting the inner diameter side lead wire portion <NUM> when performing edgewise bending of the inner diameter side lead wire portion <NUM> and a bending jig <NUM> for bending the inner diameter side lead wire portion <NUM> when performing edgewise bending of the inner diameter side lead wire portion <NUM>.

The fulcrum jig <NUM> is a member extending like a round bar and formed so as to be fitted into the gap between the inner diameter side lead wire portions <NUM> of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction. The diameter of the fulcrum jig <NUM> is substantially the same as the width in the circumferential direction of the tooth <NUM>. The fulcrum jig <NUM> is supported by a moving mechanism (not illustrated) movably in a radial direction of the stator <NUM>. Immediately before edgewise bending of the inner diameter side lead wire portion <NUM> is performed, the fulcrum jig <NUM> is moved from radially inward to radially outward of the stator <NUM> so as to be fitted into the gap between the inner diameter side lead wire portions <NUM> of the concentrically wound coils <NUM> adjacent to each other in the circumferential direction. The position to which the fulcrum jig <NUM> is moved is the position adjacent to the root portion of the inner diameter side lead wire portion <NUM>, that is, the position adjacent to the bent portion 50a in the vicinity of the connection part between the inner diameter side lead wire portion <NUM> and the slot accommodation portion <NUM>.

In addition, the bending jig <NUM> has a depression portion <NUM> that can make contact with the surface corresponding to the shorter side of the cross section of the flat conductive wire of the inner diameter side lead wire portion <NUM>. The depression portion <NUM> is a member formed in, for example, a round bar and is formed so as to be fitted into the gap between the inner diameter side lead wire portions <NUM> of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction. Before edgewise bending, the diameter of the depression portion <NUM> is made smaller than the distance between the extending portions 50e of the inner diameter side lead wire portions <NUM> of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction or the distance between the portions closer to the ends than the extending portions 50e.

The bending jig <NUM> is supported by a moving mechanism (not illustrated) movably in the radial direction and the circumferential direction of the stator <NUM>. When edgewise bending of the inner diameter side lead wire portions <NUM> is performed, the bending jig <NUM> is moved in the circumferential direction of the stator <NUM> and pushes the inner diameter side lead wire portion <NUM> in the circumferential direction while making contact with the extending portion 50e of the inner diameter side lead wire portion <NUM> or the portion closer to the end than the extending portion 50e via the depression portion <NUM>.

In the embodiment, after the slot accommodation portions <NUM> and <NUM> of all the concentrically wound coils <NUM> constituting the coil assembly <NUM> shaped like an annular cage are inserted into the slots <NUM> of the stator core <NUM>, the fulcrum jig <NUM> of the FW jig <NUM> is moved from radially outward to radially inward of the stator <NUM> so that the extending portion 50f of the inner diameter side lead wire portion <NUM> is fitted into the support portion <NUM> (<FIG>). When the extending portion 50f of the inner diameter side lead wire portion <NUM> is fitted into the support portion <NUM> of the fulcrum jig <NUM>, the bending jig <NUM> is moved from radially inward to radially outward of the stator <NUM> in the state in which the extending portion 50f is supported by the fulcrum jig <NUM> (<FIG>).

When the FW jig <NUM> is moved as described above, the inner diameter side lead wire portion <NUM> is bent using the extending portion 50f as a fulcrum so that the end side portions <NUM> and <NUM> closer to the end than the extending portion 50f topple radially outward, from the state illustrated in <FIG> and <FIG> (see <FIG> and <FIG>). The bending of the inner diameter side lead wire portion <NUM> is performed until the surface corresponding to the longer side of the cross section of the flat conductive wire of the inner diameter side lead wire portion <NUM> makes contact with the cutout portion <NUM> of the fulcrum jig <NUM>. When the bending is completed, the end side portions <NUM> and <NUM> closer to the end than the extending portion 50f of the inner diameter side lead wire portion <NUM> may extend slightly outward in the axial direction in addition to the circumferential direction and the radial direction instead of extending parallel to the end surface in the axial direction of the stator core <NUM>.

When the above FW jig <NUM> has been moved and bending has been performed, the FW jig <NUM> is returned to the waiting position by the moving mechanism.

After the bending by the movement of the above FW jig <NUM> is completed, the fulcrum jig <NUM> of the EW jig <NUM> is moved from radially inward to radially outward of the stator <NUM> so as to be fitted into the gap between the inner diameter side lead wire portions <NUM> of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction (<FIG>). After the movement is performed, the fulcrum jig <NUM> is positioned adjacently in the circumferential direction to the root portion (specifically, the bent portion 50a in the vicinity of the connection part connecting to the slot accommodation portion <NUM>) of the inner diameter side lead wire portion <NUM> of the concentrically wound coil <NUM> (the concentrically wound coil <NUM> on the right side in <FIG>, which is referred to below as the bending target concentrically wound coil <NUM>) having the fulcrum jig <NUM> in the circumferential direction (the counterclockwise in <FIG>) in which the inner diameter side lead wire portion <NUM> is crooked and bent, of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction to which the fulcrum jig <NUM> is to be fitted.

In addition, after or while the above fulcrum jig <NUM> is moved from radially inward to radially outward, the bending jig <NUM> is moved from radially inward to radially outward of the stator <NUM> so that the depression portion <NUM> is fitted into the gap between the inner diameter side lead wire portions <NUM> of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction (<FIG>). After completion of the movement, the bending jig <NUM> is positioned adjacently in the circumferential direction to the middle portion (specifically, the extending portion 50e or the portion closer to the end than the extending portion 50e) of the inner diameter side lead wire portion <NUM> of the bending target concentrically wound coil <NUM> (the concentrically wound coil <NUM> on the left side in <FIG>) having the bending jig <NUM> in the circumferential direction (the clockwise in <FIG>) opposite to the circumferential direction in which the inner diameter side lead wire portion <NUM> is crooked and bent, of the two concentrically wound coils <NUM> adjacent to each other in the circumferential direction to which the bending jig <NUM> is to be fitted.

After the movement of the above bending jig <NUM> from radially inward to radially outward, in the state in which the bent portion 50a of the inner diameter side lead wire portion <NUM> of the bending target concentrically wound coil <NUM> is supported by the fulcrum jig <NUM>, the bending jig <NUM> is moved in the circumferential direction (the counterclockwise in <FIG>) of the stator <NUM> while making contact with the middle portion of the inner diameter side lead wire portion <NUM> of the bending target concentrically wound coil <NUM> (<FIG>).

After the EW jig <NUM> is moved as described above, the inner diameter side lead wire portion <NUM> is bent using the bent portion 50a as a fulcrum in the direction (the edgewise direction in the bent portion 50a) in which the part positioned closer to the end than the bent portion 50a approaches the end surface in the axial direction of the stator core <NUM> along the circumferential direction of the stator core <NUM> (see <FIG>, <FIG>, <FIG>, and <FIG>). The bending of the inner diameter side lead wire portion <NUM> is performed until just before the surface corresponding to the longer side of the cross section of the flat conductive wire of the inner diameter side lead wire portion <NUM> makes contact with the vertex portion of the coil end portion <NUM> of another concentrically wound coil <NUM>. In the bending, the inner diameter side lead wire portion <NUM> is bent so that the bending angle of the bent portion 50a changes from a predetermined angle smaller than a final desired angle to the desired angle.

When the bending of the inner diameter side lead wire portion <NUM> is completed, the end side portions <NUM> and <NUM> of the inner diameter side lead wire portion <NUM> only need to extend parallel to the end surface in the axial direction of the stator core <NUM> and the surfaces corresponding to the longer sides of the cross sections of the flat conductive wires of the end side portions <NUM> and <NUM> only need to be formed parallel to the end surface in the axial direction of the stator core <NUM>.

When the EW jig <NUM> has been moved and bending has been performed, the EW jig <NUM> is returned to the waiting position by the moving mechanism. The bending by the movement of the EW jig <NUM> may be performed concurrently on all the concentrically wound coils <NUM> constituting the coil assembly <NUM> shaped like an annular cage as long as interference with the concentrically wound coil <NUM> adjacent in the circumferential direction is prevented (see <FIG>) or may be performed repeatedly for each of the concentrically wound coils <NUM>.

After that, the end of the inner diameter side lead wire portion <NUM> (having undergone the above bending) of the concentrically wound coil <NUM> is connected by welding or the like to the end of the outer diameter side lead wire portion <NUM> of another concentrically wound coil <NUM> disposed apart in the circumferential direction by a predetermined distance. These ends are connected to each other in the state in which the ends are oriented radially outward.

As described above, in the embodiment, after all the concentrically wound coils <NUM> constituting the coil assembly <NUM> shaped like an annular cage are attached to the stator core <NUM>, the inner diameter side lead wire portion <NUM> of each of the concentrically wound coils <NUM> may be bent so as to extend radially outward across the coil end portion <NUM> of another concentrically wound coil <NUM>. Specifically, the FW jig <NUM> is first used to perform the process of performing flatwise bending of the inner diameter side lead wire portion <NUM> entirely formed substantially concentrically as illustrated in <FIG> so that the end side portions <NUM> and <NUM> closer to the end than the extending portion 50f topple radially outward using the extending portion 50f as a fulcrum (see <FIG>). This forms a flatwise bent portion 501f (see <FIG>) in the end part of the extending portion 50f. After that, the process of using the EW jig <NUM> to perform edgewise bending of the inner diameter side lead wire portion <NUM> using the bent portion 50a (the root portion) as a fulcrum so that the part (specifically, the entire inner diameter side lead wire portion <NUM>) positioned closer to the end than the bent portion 50a approaches the end surface in the axial direction of the stator core <NUM> along the circumferential direction of the stator core <NUM> (see <FIG>).

In the stator manufacturing method using the stator manufacturing apparatus <NUM>, the FW jig <NUM> can be used to perform flatwise bending of the inner diameter side lead wire part <NUM> using the extending portion 50f as a fulcrum so that the part positioned closer to the end than the extending portion 50f topples radially outward. In the stator manufacturing method, the fulcrum jig <NUM> needs to be disposed between the vertex portion of the coil end portion <NUM> and the flatwise bent portion 501f (<FIG>), which is used as a fulcrum of flatwise bending, closer to the end than the extending portion 50f and, after the flatwise bending, the space equivalent to the thickness of the support portion <NUM> of the fulcrum jig <NUM> is formed between the vertex portion of the coil end portion <NUM> and the flatwise bent portion.

However, in the stator manufacturing method using the stator manufacturing apparatus <NUM> according to the embodiment, after flatwise bending of the inner diameter side lead wire portion <NUM> using the above FW jig <NUM>, edgewise bending of the inner diameter side lead wire portion <NUM> can be performed using the bent portion 50a, which is the root portion, as a fulcrum with the EW jig <NUM> so that the part positioned closer to the end than the bent portion 50a approaches the end surface in the axial direction of the stator core <NUM> along the circumferential direction of the stator core <NUM>.

Since the position of the end in the axial direction of the inner diameter side lead wire portion <NUM> approaches the end surface in the axial direction of the stator core <NUM> in the edgewise bending in which the bent portion 50a is used as a fulcrum, the dimension in the axial direction of the concentrically wound coil <NUM> is reduced. In addition, if the edgewise bending is performed so that the position in the axial direction of the end of the inner diameter side lead wire portion <NUM> approaches the end surface in the axial direction of the stator core <NUM> by the thickness of the support portion <NUM> of the fulcrum jig <NUM>, it is possible to reduce the space equivalent to the thickness of the support portion <NUM> of the fulcrum jig <NUM> formed between the vertex portion of the coil end portion <NUM> and the flatwise bent portion by the flatwise bending , thereby further reducing the dimension in the axial direction of the concentrically wound coil <NUM> (see <FIG>).

Therefore, in the stator manufacturing method using the stator manufacturing apparatus <NUM> according to the embodiment, the dimension in the axial direction of the entire stator <NUM> can become smaller (the structure illustrated in <FIG>) than in the structure (the structure illustrated in <FIG>) of a comparative example in which the flatwise bending of the inner diameter side lead wire portion <NUM> of the concentrically wound coil <NUM> using the extending portion 50f as a fulcrum described above is performed and the edgewise bending using the bent portion 50a as a fulcrum described above is not performed.

More specifically, as illustrated in <FIG>, in the embodiment, a bending start point Pb of the flatwise bent portion 501f of the extending portion 50f is disposed so as to overlap with the vertex portion 46a of the coil end portion <NUM> as seen in the radial direction and the extending portion <NUM> and the extending portion <NUM> (referred to below simply as the end side portions <NUM> and <NUM>) closer to the end than the extending portion 50f of the lead wire portion <NUM> are disposed parallel to the end surface of the stator core <NUM>. Here, the bending start point Pb is the position at which the lead wire portion <NUM> is bent at <NUM> degrees with respect to the end side portions <NUM> and <NUM> of the lead wire portion <NUM> and the bending start point Pb is positioned closer in the axial direction to the stator core <NUM> than the vertex portion 46a of the coil end portion <NUM>.

Here, a coil end length H is the sum of a height H1 up to the bending start point Pb and height H2 from the bending start point Pb to the end portion of the end side portions <NUM> and <NUM>. In the embodiment, height H1 can be smaller than in the case in which the bending start point Pb is positioned outward in the axial direction of the vertex portion 46a of the coil end portion <NUM>. In addition, in the embodiment, height H2 can become smaller than in the case in which the end side portions <NUM> and <NUM> are disposed obliquely outward in the axial direction instead of parallel to the end surface of the stator core <NUM>. Accordingly, in the embodiment, as illustrated in <FIG>, distance δ (space) in the axial direction between the vertex portion 46a and the end side portions <NUM> and <NUM> can be reduced. As a result, the dimension in the axial direction of the stator <NUM> can become smaller than in the case in which the bending start point Pb is positioned outward in the axial direction of the vertex portion 46a of the coil end portion <NUM>.

In the above embodiment, the inner diameter side lead wire portion <NUM> corresponds to a "lead wire portion" designated in the appended claims, the extending portion 50f corresponds to a "predetermined part" designated in the appended claims, and the bent portion 50a corresponds to a "connection part" designated in the appended claims.

In the above embodiment, the lead wire portions <NUM> and <NUM> of the concentrically wound coils <NUM> are crooked and bent before the coil assembly <NUM> is configured, as illustrated in <FIG>. However, the invention is not limited to the embodiment and the lead wire portions <NUM> and <NUM> may be crooked and bent in a shape other than that illustrated in <FIG>. However, particularly the inner diameter side lead wire portion <NUM> needs to have a part extending in the axial direction before flatwise bending so that radially outward flatwise bending is enabled and needs to have a part that topples radially outward and straddles the coil end portion <NUM> by the radially outward flatwise bending. In addition, the inner diameter side lead wire portion <NUM> only needs to be bent in advance at a predetermined angle smaller than a desired angle so as to follow the circumferential direction before the coil assembly <NUM> is configured and the concentrically wound coil <NUM> is inserted into the slots <NUM>.

<FIG> illustrates a preprocess jig included in the stator manufacturing apparatus and another embodiment of a flatwise bending process using the extending portion 50f as a fulcrum of the process of bending the lead wire portions of the concentrically wound coils using the preprocess jig. <FIG> illustrates a preprocess jig included in the stator manufacturing apparatus and another embodiment of edgewise bending using the bent portion 50a as a fulcrum of the process of bending the lead wire portions of the concentrically wound coils using the preprocess jig.

In flatwise bending, as illustrated in <FIG>, the plurality of lead wire portions <NUM> may be bent at a time or the entire circumference (all lead wire portions) may be bent at a time. In the example illustrated in <FIG>, a FW jig 60B is used in place of the FW jig <NUM> in the above embodiment. The FW jig 60B has depression portions <NUM> and the fulcrum jigs <NUM> across the entire circumference. The depression portion <NUM> is shaped like a roller as in the depression portion <NUM> of the FW jig <NUM> in the above embodiment. As in the fulcrum jig <NUM> of the FW jig <NUM> in the above embodiment, the fulcrum jigs <NUM> are moved from the outer diameter side so that the extending portions 50f of the inner diameter side lead wire portion <NUM> are fitted and are used as fulcrums when flatwise bending of the inner diameter side lead wire portions <NUM> is performed. When flatwise bending of the inner diameter side lead wire portions <NUM> is performed, the depression portions <NUM> are concurrently moved from radially inward to radially outward of the stator <NUM> and push the inner diameter side lead wire portions <NUM> radially outward while making contact with the end sides of the extending portions 50f of the inner diameter side lead wire portions <NUM>.

Claim 1:
A stator manufacturing method comprising:
a lead wire bending process of inserting a plurality of concentrically wound coils (<NUM>) into slots (<NUM>), each of the concentrically wound coils (<NUM>) being formed by winding a flat conductive wire for a plurality of turns, each of the slots (<NUM>) being formed between every two adjacent teeth (<NUM>) extending radially inward from an annular back yoke (<NUM>) of a stator core (<NUM>), wherein lead wire portions (<NUM>) of the inserted concentrically wound coils (<NUM>) projecting in an axial direction from an end surface of the stator core (<NUM>) extend in a circumferential direction while extending in the axial direction, and bending the lead wire portions (<NUM>), wherein
the lead wire bending process includes a first bending process of bending the lead wire portions (<NUM>) using, as fulcrums, predetermined parts (50f) between connection parts (50a) between the lead wire portions (<NUM>) and slot accommodation portions (<NUM>) of the concentrically wound coils (<NUM>) and ends of the lead wire portions (<NUM>), the slot accommodation portions (<NUM>) being accommodated in the slots (<NUM>), so that parts (<NUM>, <NUM>) positioned closer to the ends than the predetermined parts (50f) topple radially outward, characterized in that
the lead wire bending process further includes, after the first bending process, a second bending process of bending the lead wire portions (<NUM>) using the connection parts (50a) as fulcrums so that the lead wire portions (<NUM>) approach the end surface of the stator core (<NUM>) along the circumferential direction of the stator core (<NUM>).