Coil segment processing method, coil segment processing apparatus and connection structure of coil segments

The innermost first segment layer and the second segment layer adjacent thereto in a radial direction are twisted using a twisting jig unit including an inner twisting jig and an outer twisting jig, then the twisting jig unit is replaced with another twisting jig unit including an inner twisting jig and an outer twisting jig, and the third segment layer and the fourth segment layer adjacent thereto are twisted, and then the twisting jig unit is replaced with still another twisting jig unit including an inner twisting jig and an outer twisting jig, and the fifth segment layer and the sixth segment layer adjacent thereto are twisted.

TECHNICAL FIELD

The present invention relates to a coil segment processing method for twisting and bending end portions of coil segments protruding from an end face of a core of a stator or a rotor of an electrical rotating machine (rotating electric machine) such as a motor or a power generator, a coil segment processing device configured to perform the coil segment processing method, and a connection configuration of coil segments.

BACKGROUND ART

As a coil of a stator or a rotor in an electrical rotating machine, so-called segment type coil is well known. In such a segment type coil, a plurality of coil segments (hereinafter, simply referred to as “segment(s)”) respectively formed by processing a linear wire rod of a predetermined length into a U-shape are inserted into a plurality of slots arranged along a circumferential direction of the stator or rotor, respectively, and the free end sides of these segments (end sides in the insertion direction; hereinafter referred to as “segment end portion(s)”) are twisted and electrically connected to one another by welding or the like. Some of the plurality of segment end portions are connected as power supply lines. This type of coil segment is also referred to as a hairpin.

As the twisting process of the segment end portions of the segment type coils, for example, as shown inFIG.5andFIG.6of PTL1, it is known that a plurality of cylindrical (annular) twisting jigs having through holes or grooves for inserting the segment end portions therein are concentrically arranged, and the segment end portions of multiple layers are simultaneously twisted by rotating each of these jigs in a predetermined direction.

In PTL1, a four-layer configuration of accommodating four segments in every slot of the stator iron core is exemplified, and correspondingly, the twisting jig is configured such that four twisting jigs are concentrically arranged.

The apparatus of PTL1 is configured such that twisting jigs of the first layer and the third layer, from the center to the outside in the radial direction, are synchronously rotated in one direction, and twisting jigs of the second layer and the fourth layer are rotated synchronously in the opposite direction to the one direction. In other words, the configuration is such that the twisting jigs of adjacent layers in the radial direction are rotated in different directions to twist, and the segment end portions of all layers (four layers here) are simultaneously twisted.

In this type of twist process, the twisting jigs are rotated while moving the workpiece (a stator or a rotor) straight to the twisting jig side, that is, inserting the segment end portions into the twisting jig and pressing them.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

Here, in a coil configuration in which a plurality of segment layers spread concentrically, since the number of segments arranged in the circumferential direction is the same in each layer, the distance between the segments in the circumferential direction is different between the inner layers and the outer layers in the radial direction. Then, in order to electrically connect the segment end portions of the adjacent layers after twisting, it is necessary to increase the protrusion amount (length) of the segment end portions from the end face of the core as it goes outward in the radial direction. Depth of insertion holes or insertion grooves of each twisting jig is set corresponding to the variation in length of the segment end portions.

As described above, since the protrusion amount of the segment end portions from the end face of the core is different between the inner side and the outer side in the radial direction, a relationship characteristic between a straight movement of the workpiece and a rotation angle of the twisting jig at the time of the twisting (hereinafter, referred to as “twist characteristic”) inevitably differs depending on the length of the segment end portions.

However, in the method described in PTL1, which simultaneously twists the segment end portions of a plurality of layers, twisting is performed in a state where the twisting characteristics are biased because the twisting jigs at different radial positions, in other words, the segment end portions with different twisting characteristics are synchronously rotated.

That is, when setting the rotation amount of the twisting jigs with reference to the twist characteristic of the segment end portions of the inner side in the radial direction, the rotation amount of the segment end portions of the outer side is insufficient and thus accuracy of the twisting decreases. Conversely, when setting the rotation amount of the twisting jigs with reference to the twist characteristic of the segment end portions of the outer side in the radial direction, the rotation amount of the segment end portions of the inner side is excessive and thus accuracy of the twisting decreases.

As a result, overall accuracy of the twisting was low. Lower accuracy of twisting affects also accuracy of connection between the segment end portions by welding or the like and connection (wiring) of the segment end portions for power supply lines or the like, thus resulting in a deterioration in a quality of the electrical rotating machine such as a motor.

Further, in the method described in PTL1, which simultaneously twists the segment end portions of a plurality of layers, since the adjacent layers in the radial direction are twisted in opposite directions, it was unavoidable that the distance between the segments for power supply lines in different layers becomes large (distant) after the twisting. Therefore, it was necessary to employ a complicated connection configuration of the power supply lines for electrically connecting a plurality of segments for power supply lines using long conductors extending in the circumferential direction. The complicated connection configuration of the power supply line leads to decreased reliability.

The invention has been developed in view of the above situation, for the purpose of enabling to accurately twist segment end portions of a plurality of coil segments inserted into slots of a core of a stator or a rotor, protruding from the end face of the core to form a plurality of layers. Another purpose of the invention is to realize a highly reliable electrical rotating machine.

Solution to Problem

In order to achieve the above purpose, in view of the fact that the conventional problem arises from simultaneous twisting of the layers from that on the inner side in the radial direction where the protrusion length of the segment end portion is the shortest to that on the outer side where the protrusion length of the segment end portion is the longest, the present invention performs the twisting as a process divided into several times, and as a result, good twist accuracy over all the layers is obtained.

Namely, a coil segment processing method according to the present invention is a coil segment processing method for processing a plurality of coil segments inserted into slots of a core of a stator or a rotor, comprising performing twisting to the plurality of coil segments inserted into the slots such that segment end portions that are end portions of the respective coil segments protruding from an end face of the core form a plurality of layers in a radial direction of the core, using a plurality of twisting jig units respectively comprising a smaller number of twisting jigs than total number of the plurality of the layers, the twisting jigs being concentrically disposed, each of the twisting jigs corresponding to any one of the plurality of layers respectively and comprising accommodating portions configured to respectively accommodate the segment end portions of the corresponding layer, wherein the twisting comprises a twist process of accommodating, into the accommodating portions of each twisting jig of one of the plurality of twisting jig units, the segment end portions of each layer corresponding to the each twisting jig, respectively, and rotating the each twisting jig so as to twist the accommodated segment end portions, and wherein the twisting comprises sequentially performing the twist process using each of the plurality of twisting jig units so as to twist segment end portions of all of the layers.

In this coil segment processing method, it is conceivable that the twisting process using a first twisting jig corresponding to a predetermined layer among the twisting jigs is performed in a state that a position in the radial direction of a particular segment end portion among a plurality of segment end portions of the predetermined layer is shifted to a position different from that of other segment end portions of the predetermined layer so that the particular segment end portion is not accommodated into any of the accommodating portions of the first twisting jig.

In this case, it is conceivable to selectively push the particular segment end portion by a pushing member to a position where the particular segment end portion does not interfere at least with the first twisting jig during the twist process using the first twisting jig, prior to the twist process using the first twisting jig.

It is conceivable that the pushing by the pushing member is performed after displacing the particular segment end portion in the radial direction by a displacing member different from the pushing member.

It is conceivable that the coil segment processing method comprises expanding a space in the radial direction between the segment end portions of each layer to be twisted by a twisting jig unit including the first twisting jig and the segment end portions of other layers, prior to the accommodating of the segment end portions into the accommodating portions of the first twisting jig, wherein a member that interferes with the segment end portions and moves the segment end portions in the expanding is used as the displacing member.

It is conceivable that the predetermined layer is an outermost layer and/or an innermost layer in the radial direction among the plurality of layers.

It is conceivable that: a first long segment end portion exists in an innermost layer in the radial direction, the first long segment end portion protruding from the end face of the core longer than other segment end portions of the innermost layer; and a second long segment end portion exists in an outermost layer in the radial direction, the second long segment end portion protruding from the end face of the core longer than other segment end portions of the outermost layer; the twist process regarding the innermost layer is performed using a first twisting jig corresponding to the innermost layer such that the first long segment end portions and said other segment end portions of the innermost layer are twisted in a same twisting direction; and the twist process regarding the outermost layer is performed such that, after shifting a position in the radial direction of the second long segment end portion to a position different from that of other segment end portions of the outermost layer, said other segment end portions of the outermost layer are twisted in a twisting direction opposite to the twisting direction of the segment end portions of the innermost layer using a second twisting jig corresponding to the outermost layer, and then the second long segment end portion is twisted in a direction same as the twisting direction of the segment end portions of the innermost layer using a third twisting jig other than the second twisting jig so that the second long segment end portion almost opposes to the first long segment end portion.

It is conceivable, regarding each of the plurality of the twisting jig units, to expand a space in the radial direction between the segment end portions of each layer twisted by the twisting jig unit and the segment end portions of other layers, prior to the accommodating of the segment end portions into the accommodating portions of twisting jigs of the twisting jig unit.

It is conceivable that each of the plurality of twisting jig units is held by a unit holder which is movably supported, and that when performing the twist process using each of the plurality of twisting jig units, a twisting jig unit to be used for the twist process is changed by moving the unit holder and connecting one twisting jig unit selected among the plurality of twisting jig units with a rotary drive mechanism to rotate each twisting jig of the selected one twisting jig unit.

Further, a coil segment processing apparatus according to the present invention is a coil segment processing apparatus configured to process a plurality of coil segments inserted into slots of a core of a stator or a rotor, the plurality of coil segments being inserted into the slots such that segment end portions that are end portions of the respective coil segments protruding from an end face of the core form a plurality of layers in a radial direction of the core, comprising: a plurality of twisting jig units respectively comprising a smaller number of twisting jigs than total number of the plurality of the layers, the twisting jigs being concentrically disposed, each of the twisting jigs corresponding to any one of the plurality of layers respectively and comprising accommodating portions configured to respectively accommodate the segment end portions of the corresponding layer; a driving mechanism configured to move one twisting jig unit and/or the core with the coil segments inserted thereinto so as to accommodate, into the accommodating portions of each twisting jig of the one twisting jig unit selected from the plurality of the twisting jig units, the segment end portions of layers corresponding to the each twisting jig, respectively; and a rotary drive mechanism connectable to a twisting jig unit arbitrarily selected from the plurality of the twisting jig units and configured to rotate each twisting jig of a twisting jig unit connected thereto in a rotating direction opposite to that of radially adjacent twisting jig.

It is conceivable that the coil segment processing apparatus comprises a pushing member configured to selectively push a particular segment end portion among a plurality of segment end portions of a predetermined layer among the plurality of the layers to a position where the particular segment end portion does not interfere at least with a first twisting jig corresponding to the predetermined layer so that the particular segment end portion is not accommodated into any of accommodating portions of the first twisting jig even when the segment end portions of the predetermined layer are to be accommodated into the accommodating portions of the first twisting jig by the driving mechanism.

It is conceivable that the predetermined layer is an outermost layer and/or an innermost layer in the radial direction among the plurality of layers.

It is conceivable that the coil segment processing apparatus comprises a unit holder that is movably supported and configured to hold each of the plurality of twisting jig units, wherein one twisting jig unit selected among the plurality of twisting jig units is connected with the rotary drive mechanism due to movement of the unit holder.

It is conceivable that a concave portion is formed on either one of the rotary drive mechanism and the plurality of the twisting jig units, and a convex portion to be fitted to the concave portions is formed on the rotary drive mechanism or the plurality of the twisting jig units to be connected to the either one, and that rotary driving force is transmitted from the rotary drive mechanism to the twisting jig unit connected to the rotary drive mechanism through connection between the concave portion and the convex portion due to the movement of the unit holder.

It is conceivable that, in at least one twisting jig unit among the plurality of the twisting jig units, an axis of one twisting jig comprised in the at least one twisting jig unit passes through an axis of another twisting jig comprised in the at least one twisting jig unit.

It is conceivable that the coil segment processing apparatus comprises an interlayer spacing mechanism configured to expand a space in the radial direction between the layers with each number of layers to be twisted using one twisting jig unit.

It is conceivable that the interlayer spacing mechanism comprises a plurality of handling members disposed radially to correspond to the respective slots and integrally movable in the radial direction, and configured to interfere with segment end portions inserted to the corresponding slots so as to move the segment end portions respectively.

Further, a connection structure of coil segments according to the present invention comprises: a core of a stator and/or a rotor; and a plurality of coil segments inserted into slots of the core, the plurality of coil segments being inserted into the slots such that segment end portions that are end portions of the respective coil segments protruding from an end face of the core form a plurality of layers in a radial direction of the core, wherein the segment end portions include: first segment end portions twisted in a circumferential direction of the core; and second segment end portions extending in an axial direction of the core from an end of the core, and the second segment end portions substantially opposing to each other in the radial direction are connected with each other via a conductor.

Another connection structure of coil segments according to the present invention comprises: a core of a stator and/or a rotor; and a plurality of coil segments inserted into slots of the core, the plurality of coil segments being inserted into the slots such that segment end portions that are end portions of the respective coil segments protruding from an end face of the core form a plurality of layers in a radial direction of the core, wherein the segment end portions include short segment end portions and long segment end portions protruding longer from the end face of the core than the short segment end portion of same layer, a first long segment end portion existing in a first layer among the plurality of layers is twisted, in a circumferential direction of the core, in same twisting direction as a twisting direction of the short segment end portions of the first layer, a second long segment end portion existing in a second layer different from the first layer among the plurality of layers is twisted, in a circumferential direction of the core, in same twisting direction as the twisting direction of the first long segment end portion that is opposite to a twisting direction of the short segment end portions of the second layer, and the first long segment end portion and the second long segment end portion substantially oppose to each other in the radial direction and are connected with each other via a conductor.

Effect of the Invention

According to the present invention, it is possible to accurately twist segment end portions of a plurality of coil segments inserted into slots of a core of a stator or a rotor, protruding from an end face of a core to form a plurality of layers. Further, it is possible to realize a highly reliable electrical rotating machine.

DESCRIPTION OF EMBODIMENTS

Hereinafter embodiments of the present invention will be described with reference to the drawings. First, a first embodiment will be described with reference toFIG.1toFIG.11C.

An example of an object of twisting by a later-described coil twisting apparatus that is one embodiment of a coil segment processing apparatus is, as shown inFIG.3, portions protruding from an end face of a core72aamong U-shaped coil segments inserted into slots72bof a stator72(hereinafter, also referred to as “workpiece”) with insulating papers79between them, i.e. a group of segment end portions12p(when not specifying an individual of the segment end portion, reference sign “12p” is used).

Each coil segment used here has U-shape in which two linear slot insertion portions to be inserted into the slots72bare connected via a linking portion bent in a crank shape. In a state shown inFIG.3, respective slot insertion portions are inserted into different slots72b, and the segment end portions12pwhich are end portions of respective slot insertion portions protruding from an end face of the core72aform a plurality of layers (here, six layers) in the radial direction of the core72a. This “layer” is also referred to as a “segment layer” hereinafter. Two segment end portions12pin one coil segment may belong to different segment layers.

InFIG.3, the reference sign12p1indicates a segment end portion in the innermost layer, and the reference sign12p6indicates a segment end portion in the outermost layer. This example shows an example that the number of the coil segment layers is six, but the present invention is not limited thereto. In a coil segment processing method of the present embodiment, each two adjacent layers in the radial direction of the core72ais twisted through a twist process using a separate twisting jig unit in sequence from the inner side, and in the case of six layers, the twist process is performed three times in total.

That is, the segment end portions of all the layers are twisted by performing a plurality of twist process over the entire plurality of layers while changing the twisting jig units.

As described above, in the coil configuration in which a plurality of segment layers (here, six layers) extend concentrically, since the arrangement number of segments in the circumferential direction is the same for each layer, the distance between the segments in the circumferential direction is different between radially inner layers and outer layers.

Therefore, in order to enable connection between segment end portions of different layers after the twisting, amount of protrusion (height) of the segment end portions from the end face of the core should be increased toward the outside in the radial direction.

As shown inFIG.4, difference in height between the innermost segment layer12L1and the adjacent segment layer12L2is h, and the difference in height between the innermost segment layer12L1and the outermost segment layer12L6is H, for example, about five times as much as h. In the following description, the segment layer12Ln is also referred to as an “n-th layer”.

When twisting the segment layers12L1to12L6, it is conceivable to synchronously rotate the segment layers12L1,12L3, and12L5in the same direction, and synchronously rotate the segment layers12L2,12L4, and12L6in the opposite direction to the above, so that all the layers are twisted simultaneously.

Such twisting can be performed by rotating the twisting jigs while raising the workpiece toward the twisting jigs. However, good twisting accuracy in all layers cannot be obtained with this method because the twist characteristics vary depending on the difference in the amount of protrusion of the segment end portion as described above.

InFIG.4, the segment end portions of each layer are shown only in a partial region. In addition, spaces between the layers are enlarged for ease of understanding. The upper end portions (white portions) of each segment end portions12p1to12p6show peeled-off portions where insulation coating thereof is peeled off. The coil segments except of the peeled-off portions are covered with the insulation coating. As long as insulation is possible, a member other than the insulation coating may be adopted.

As shown inFIG.4, the difference h of the height between segment end portions of adjacent layers in the radial direction of the core is extremely small. Hence it can be said that influence on the twisting accuracy because of the difference in height is little, even if these layers are twisted at the same time.

The present invention focuses on this point and performs the twist process causing very little influence because of the difference in height between the segment end portions, over all the layers by dividing the twisting into multiple times, in order to improve the twisting accuracy and, consequently, output of the motor including the manufactured coil, even though it takes a certain amount of time.

In the present embodiment, two layers adjacent to each other in the radial direction of the core are handled as one group, and twist process is performed three times. Therefore, the twist processing of the innermost segment layer12L1and the segment layer12L2adjacent thereto is firstly performed at the same time such that the respective twisting directions are opposite to each other in adjacent layers in the radial direction of the core.

The state after this twist process is shown inFIG.5. Next, as will be described later, the twisting jig unit is replaced with another twisting jig unit having different diameters (D1to D6), and twist process of the segment layer12L3and the adjacent segment layer12L4is performed at the same time so that the respective twist directions are opposite to each other in adjacent layers in the radial direction of the core. Next, the twisting jig unit is similarly replaced with still another twisting jig unit having different diameters and twist process of the segment layer12L5and the adjacent segment layer12L6is performed at the same time so that the respective twist directions are opposite to each other in adjacent layers in the radial direction of the core.

The above-mentioned three twist processes will be described in detail with reference toFIG.1. As shown by (a) and (b) inFIG.1, firstly, the segment layer12L1and the adjacent segment layer12L2are simultaneously twisted to opposite directions using the twisting jig unit28A The twisting jig unit28A includes: an inner twisting jig50, corresponding to the segment layer12L1to which the segment end portions12p1of the innermost segment layer12L1are inserted; and an outer twisting jig51, corresponding to the segment layer12L2, to which the segment end portions12p2of the segment layer12L2are inserted.

As shown inFIG.2, the inner twisting jig50is in a cylindrical shape. A plurality of mounting holes50bfor fixing the inner twisting jig50to the body of the twisting jig unit28A described later and an insertion hole50cfor a rotary shaft are formed on the upper surface50aof the inner twisting jig50.

Insertion grooves50das accommodating portions configured to receive insertion of respective segment end portions12p1of the segment layer12L1are formed in the same number as the number of the segments, at equal intervals in the circumferential direction, on the outer peripheral surface of the lower end portion of the inner twisting jig50.

An outer twisting jig51has a cylindrical shape fitted to the outer surface of the inner twisting jig50. A flange portion51afor fixing the outer twisting jig51to the body of the twisting jig unit28A is formed at the upper end of the outer twisting jig51. A plurality of mounting holes51bare formed at equal intervals in the circumferential direction in the flange portion51a.

Insertion grooves51cas accommodating portions configured to receive insertion of respective segment end portions12p2of the segment layer12L2are formed in the same number as the number of the segments, at equal intervals in the circumferential direction, on the inner peripheral surface of the outer twisting jig51.

It is possible to insert (accommodate) the segment end portions12p1of the segment layer12L1into the insertion grooves50dof the inner twisting jig50and insert (accommodate) the segment end portions12p2of the segment layer12L2into the insertion grooves51cof the outer twisting jig51by moving the twisting jig unit28A and/or the work72, whereby relatively bringing the twisting jig unit28A and the work72closer.

In the present embodiment, a method is employed in which the work72is raised by a lifting mechanism described later, and respective segment end portions12p1,12p2, are inserted into the inner twisting jig50and the outer twisting jig51of the twisting jig unit28A fixed on the upper side. Namely, saving of energy is attempted by moving the lightweight configuration side.

The twist process is performed by rotating the inner twisting jig50and the outer twisting jig51while raising the workpiece72. That is, the twisting jig unit28A is connected to a rotary drive mechanism described later to transmit its driving force, and as shown by (a) inFIG.1, for example, the inner twisting jig50is driven to rotate in a clockwise direction (direction of arrow R1), the outer twisting jig51is driven to rotate in a counterclockwise direction (direction of arrow R2) which is the opposite direction. Thus, each segment end portion12p1of the segment layer12L1and each segment end portion12p2of the segment layer12L2are twisted in opposite directions, respectively.

When the twist process of the segment end portions of the segment layer12L1and the segment layer12L2is completed, as shown by (c) and (d) inFIG.1, in order to twist the segment end portions of the segment layer12L3and the segment layer12L4adjacent thereto in the radial outward direction, the twisting jig unit28A connected to the rotary drive mechanism is replaced with the twisting jig unit28B corresponding to the pair of the segment layer12L3and the segment layer12L4, and the same twist process as above is performed.

Twisting jig unit28B includes an inner twisting jig52having a diameter larger than that of the inner twisting jig50of the twisting jig unit28A, and an outer twisting jig53having a diameter larger than that of the outer twisting jig51of the twisting jig unit28A.

The inner twisting jig52and the outer twisting jig53respectively have the same configurations as those of the inner twisting jig50and the outer twisting jig51described above, only with different diameters. The segment end portions12p3of the segment layer12L3are inserted into the insertion grooves of the inner twisting jig52, and the segment end portions12p4of the segment layer12L4are inserted into the insertion grooves of the outer twisting jig53.

In this state, the inner twisting jig52is driven to rotate in a clockwise direction (direction of arrow R1), and the outer twisting jig53is driven to rotate in a counterclockwise direction (direction of arrow R2). As a result, the segment end portions12p3of the segment layer12L3and the segment end portions12p4of the segment layer12L4are twisted in opposite directions, respectively.

When the twist process of the segment end portions of the segment layer12L3and the segment layer12L4is completed, as shown by (e) and (f) inFIG.1, in order to twist the segment end portions of the segment layer12L5and the segment layer12L6, the twisting jig unit28B connected to the rotary drive mechanism is replaced with the twisting jig unit28C corresponding to the pair of the segment layer12L5and the segment layer12L6, and the same twist process as above is performed.

Twisting jig unit28C includes an inner twisting jig54having a diameter larger than that of the inner twisting jig52of the twisting jig unit28B, and an outer twisting jig55having a diameter larger than that of the outer twisting jig53of the twisting jig unit28B.

The inner twisting jig54and the outer twisting jig55respectively have the same configurations as those of the inner twisting jig50and the outer twisting jig51of the twisting jig unit28A, only with different diameters. The segment end portions12p5of the segment layer12L5are inserted into the insertion grooves of the inner twisting jig54, and the segment end portions12p6of the outermost segment layer12L6are inserted into the insertion grooves of the outer twisting jig55.

In this state, the inner twisting jig54is driven to rotate in a clockwise direction (direction of arrow R1), and the outer twisting jig55is driven to rotate in a counterclockwise direction (direction of arrow R2). As a result, the segment end portions12p5of the segment layer12L5and the segment end portions12p6of the segment layer12L6are twisted in opposite directions, respectively.

As described above, in the present embodiment, only a fewer number of segment layers (two layers here) than the total number of layers, adjacent to one another in the radial direction of the core, are twisted at the same time, so that the twist process of all the segment layers can be performed under the optimum conditions that are suitable for the segment layers to be twisted in each twist process without being affected by the difference in the height of the segment end portions. Preferable conditions for each segment layer may be determined in advance by experiment or the like and set in the coil twisting apparatus. The smaller the number of layers to be twisted at the same time is, the more the influence of the height difference of the segment end portions can be reduced.

That is, height difference between segment end portions of the innermost segment layer and those of the outermost segment layer in the radial direction may be extremely large in some coils, but even in such a case fine twist process can be performed. This means, in other words, that the height of the segment end portions can be adjusted.

Although the method ofFIG.1requires to replace twisting jig unit several times and thus more time and effort is necessary than the method of twisting all layers at the same time, the method ofFIG.1can improve accuracy of the twist process and consequently can improve output of a motor including the manufactured coil. If the influence on the twist accuracy is small, one twisting jig unit may be configured to have three or more twisting jigs. That is, the twisting may be performed while replacing the twisting jig unit for each three or more layers. Conversely, one twisting jig unit may be configured to have only one twisting jig. Further, number of twisting jigs comprised in one twisting jig unit may vary for each twisting jig unit. That is, a configuration in which two layers are twisted and then four layers are twisted may be employed.

Further, in the method ofFIG.1, as compared with the method of twisting all layers at the same time, since the number of twisting jigs in one twisting jig unit is small, it is possible to increase thickness of each twisting jig to improve strength against the load at the time of twist process.

That is, in the method of twisting all layers at the same time, each twisting jig must be thin in consideration of weight reduction and output of the drive source, and thus insufficient strength of the twisting jigs is concerned. However, the present invention can solve this problem.

Hereinafter, the configuration and the like relating to the rotary drive of the twisting jigs in the coil twisting apparatus of the present embodiment is described in detail.

First, an overview of the configuration of the coil twisting apparatus15of the present embodiment will be described with reference toFIG.6toFIG.9.FIG.6is a front view,FIG.7is a side view,FIG.8is a plan view.

The coil twisting apparatus15has: a rectangular shaped base16as a base; two props17arranged on the left and right of the front side on the base16and extending in the vertical direction; a vertical plate18arranged on the back side of the base16and extending in the vertical direction; a top plate19horizontally supported above the base16by the props17and the vertical plate18; a rotary drive mechanism20arranged on the top plate19; a lift mechanism21for lifting up and down a workpiece mounted with the segment end portions protruding upward; a twisting jig replacing unit22provided with a plurality of types of twisting jig units; an interlayer spacing member23for spreading a space between the respective layers of the coil segments (space between every two layers here) to facilitate insertion of the segment end portions into the twisting jigs before inserting the segment end portions into the twisting jigs; and the like.

Bolt screws43for height adjustment are provided at four corners of the base16and the central portion of the longitudinal direction of the base16, so that the inclination of the upper surface of the base16can be adjusted.

As shown inFIG.7, the rotary drive mechanism20has: a drive mechanism portion25of a concentric two-axis configuration whose mating convex portion24is fixed on the top plate19so as to protrude to the lower surface side of the top plate19; an inner servomotor26as a first drive source configured to rotate the inner axis member having the mating convex portion24; and an outer servomotor27(seeFIG.6) as a second drive source configured to rotate the outer axis member.

The twisting jig replacing unit22has: a plurality of twisting jig units28A,28B,28C and28D; a long-plate shaped unit holder29integrally supporting the twisting jig units; and a linear motion guide30configured to smoothly slide the unit holder29horizontally.

The linear motion guide30has: four support blocks31fixed in two rows on the lower surface of the top plate19; a linear guide32fixed between the support blocks31like a bridge; and two rail members48fixed to the upper surface of the unit holder29and sliding in the linear guide32.

On the upper surface of each twisting jig unit28A,28B,28C and28D, a mating concave portion33to be mated with the mating convex portion24is formed. When the unit holder29is slid and stopped at a predetermined position, the mating concave portion33of one of the twisting jig units28A,28B,28C and28D is mated with the mating convex portion24. By stopping the unit holder29at a position corresponding to the desired twisting jig unit, the twisting jig unit is connected to the rotary drive mechanism20, and thereby rotation of the rotary drive mechanism20can be transmitted to each twisting jig comprised in the twisting jig unit.

Positioning plates34respectively having insertion holes34afor a lock pin35, corresponding to each twisting jig unit28A,28B,28C and28D, are fixed to the unit holder29.

The lock pin35is provided on the front side of the apparatus on a bracket44fixed to the top plate19. When any of the twisting jig unit28A,28B,28C and28D is set to a predetermined position, by inserting the lock pin35into the insertion holes34aof the positioning plate34corresponding to the set twisting jig, the twisting jig unit set to the predetermined position is locked at a position to perform the twist process of the segment end portions.

As shown inFIG.6, handles45for sliding the unit holder29are attached at both ends of the longitudinal direction (lateral direction in the drawing) of the unit holder29. The twisting jig replacing unit22in this embodiment employs a manual system in which the twisting jig units are replaced by pushing by hand.

FIG.6shows a state in which the twisting jig unit28A is set to the predetermined position to perform the twist process. For example, to replace the twisting jig unit in this state to the twisting jig unit28D at the left end, the unit holder29needs to be moved to the right side ofFIG.6until the twisting jig unit28D comes to the position where the twisting jig unit28A exists inFIG.6. Accordingly, the unit holder29protrudes from the main body of the coil twisting apparatus15to the right side inFIG.6in this state.

Replacement operation of the twisting jig unit is not removing the twisting jig unit which is heavy object. As described above, the replacement operation is merely sliding the unit holder29which supports the plurality of twisting jig units28A,28B,28C and28D via the linear motion guide30with little sliding resistance, and mating the mating convex portion24of the rotary drive mechanism20with the mating concave portion33on the twisting jig side, which is a simple operation with small effort.

The replacement operation may be automated such that the unit holder29is slid a predetermined amount by a drive source such as a servomotor capable of position controlling, and the lock pin is inserted by means such as a solenoid to fix the position of the unit holder29.

The configuration relating to transmission of the rotary driving force through the concentric two-axis configuration in the rotary drive mechanism20will be briefly described.

In the rotary drive mechanism20, the inner rotary axis (one of the two axes) extending in the vertical direction is driven to rotate by the inner servomotor26through a deceleration mechanism or the like, and the outer rotary axis (the other of the two axes) is driven to rotate by the outer servomotor27through a deceleration mechanism or the like.

Convex portions constituting the mating convex portion24are individually formed at the lower ends of the inner rotary axis and the outer rotary axis, respectively.

The twisting jig unit28A has an inner cylinder to which rotation of the inner rotation axis is transmitted and an outer cylinder to which rotation of the outer rotation axis is transmitted, and concave portions constituting the mating concave portion33are individually formed at the upper ends of the inner cylinder and the outer cylinder, respectively. The inner cylinder penetrates inside the outer cylinder, an inner twisting jig50of the twisting jig unit28A is attached to the lower end of the inner cylinder, and an outer twisting jig51of the twisting jig unit28A is attached to the lower end of the outer cylinder.

Therefore, the inner twisting jig50can be rotated in one direction with the inner cylinder as an axis by the inner servomotor26, and the outer twisting jig51can be rotated in the opposite direction with the outer cylinder as an axis by the outer servomotor27. Other twisting jig units28B,28C and28D also have the same configuration.

Referring toFIG.9, a configuration relating to the connection between the rotary drive mechanism20and the twisting jig unit28A by mating of concave and convex is described.

One inner mating convex portion24ain a rectangular shape is formed integrally with the inner rotary axis at the lower end of the inner rotary axis, and a pair of outer mating convex portions24bare formed at opposing positions in the radial direction integrally with the outer rotary axis at the lower end of the outer rotary axis. The mating convex portion24of the rotary drive mechanism20side is configured by an arrangement of the one inner mating convex portion24aand the two outer mating convex portions24bin a row. Reference numeral58aindicates the lower end surface of the inner rotating axis.

A pair of inner mating concave portions62ato be mated with the inner mating convex portion24aare formed at the upper end of the inner cylinder62of the twisting jig unit28A at positions in the radial direction corresponding to the inner mating convex portion24a.

A pair of outer mating concave portions63ato be mated with the outer mating convex portions24bare formed on the upper face of the outer cylinder63of the twisting jig unit28A at positions in the radial direction corresponding to the outer mating convex portions24b.

The mating concave portion33of the twisting jig unit28A side is configured by an arrangement of the two inner mating concave portions62aand the two outer mating concave portions63bin a row. Other twisting jig units28B,28C and28D also have the same configuration.

In the present embodiment, the mating convex portion is formed on the rotary drive mechanism side and the mating concave portion is formed on the twisting jig unit side, but conversely, the mating concave portion may be formed on the rotary drive mechanism side and the mating convex portion may be formed on the twisting jig unit side.

As shown inFIG.10andFIG.11AtoFIG.11C, the interlayer spacing member23has a plurality of rod-shaped handling members74arranged radially in a horizontal plane. The interlayer spacing member23is a member configured to expand a space between the layers of the coil segments by every two layers before the twist process by moving the handling members74simultaneously in the radial direction and the vertical direction (axial direction) of the core.

In a state immediately after inserting the respective coil segments into the slots72bat the time when firstly placed on the lifting table36of the coil twisting apparatus15(seeFIG.6), segment end portions of respective layers are close to one another in the radial direction, and if the segment end portions are attempted to be inserted into the insertion portions of the twisting jigs in this state, the insertion may be hindered by the adjacent segment end portions, resulting in failure. The interlayer spacing member23is provided to address this point.

As shown inFIG.10, each handling member74includes: a connecting axis74ato the drive source configured to move the handling member74simultaneously in the radial direction; a concave portion74bformed at the inner tip portion in the radial direction; and an insertion hole74c.

Each handling member74is connected with a cam member (not shown) through the connecting axis74a, and when the cam member is rotated by the drive source, a plurality of handling members74move simultaneously in the radial direction (X direction). Further, each handling member74is movable in the vertical direction (Z direction; the longitudinal direction of the segment end portion) integrally by a mechanism described later.

Referring toFIG.11AtoFIG.11C, handling operation by the interlayer spacing member23will be described. In this handling operation, firstly, as shown inFIG.11A, the vertical level and the radial position of each handling member74are adjusted so that the segment end portions12p3of the segment layer12L3, the segment end portions12p4of the segment layer12L4, the segment end portions12p5of the segment layer12L5and the segment end portions12p6of the segment layer12L6are inserted in each insertion hole74cthereof.

Next, as shown inFIG.11B, each handling member74is moved outward in the radial direction, and then lowered so that a space between the segment layers12L1,12L2and the segment layers12L3,12L4is expanded. At this time, each handling member74interferes with the segment end portions12p3of the segment layer12L3as it descends, causing the segment end portions12p3to move outward in the radial direction. Further, the segment end portions12p3move the segment end portions12p4to12p6of the outer segment layers outward in the radial direction.

Even if the bottom surface of each handling member74(lower surface in the figure) is lowered to a position lower than the tip of the segment end portions of the segment layer12L1and the segment layer12L2, the segment end portions of these segment layers do not interfere with the handling member74because they are accommodated in the concave portion74b. The expanding width W is determined such that the insertion into the insertion portions (hole or groove, etc.) of the twisting jigs can be reliably performed in consideration of the recovery after the expanding (spring back).

As shown inFIG.11C, the fifth layer and the sixth layer can be expanded by the same operation as described above.

The operation of the interlayer gap formation by the interlayer spacing member23is performed after the segment end portions are opposed to the twisting jigs by raising the workpiece by the lift mechanism21described below.

By performing the handing operation (interlayer gap formation) by the interlayer spacing member23, the layers are spaced in the radial direction of the core for each two layers to be twisted with one twisting jig unit, and thus insertion of the segment end portions to each twisting jig unit can be performed with high accurately.

Thus, as compared with the case where the segment end portions of each layer are close to one another in the radial direction, complexity and trouble of alignment of the segment end portions with respect to the twisting jigs can be reduced. It is possible to improve work efficiency in the twist process, and eventually it is possible to contribute to improvement of manufacturing efficiency of rotary electric machines.

As shown inFIG.6andFIG.7, the lift mechanism21has: the lifting table36configured to place a workpiece thereon, a servomotor37as a drive source configured to raise and lower the lifting table36; a driving force converting portion49configured to convert the rotation of the servomotor37into movement in the vertical direction of the support axis36aof the lifting table36; and a linear motion guide38provided in the vertical plate18to guide the raising and lowering of the lifting table36.

The linear motion guide38has two rails39fixed in parallel to each other on the front side of the vertical plate18and extending in the vertical direction, and sliders40configured to slide on the rails39. The lifting table36is supported by the sliders40.

A member indicated by the reference numeral41inFIG.7is a pallet conveying guide configured to place a pallet loaded with the work on the lifting table36of the lifting mechanism21. As shown inFIG.8, the member has a plurality of rollers42on both sides, so that the pallet loaded with the work can move smoothly to the lifting table36side (arrow T direction).

A plurality of rollers whose levels are substantially the same as the rollers42of the pallet conveying guide41are provided on both sides of the lifting table36, and the pallet can be smoothly moved from the pallet conveying guide41to the lifting table36.

When performing processing according to an embodiment of the coil segment processing method of the invention on coil segments by the coil twisting apparatus15, a workpiece72assembled by a coil assembling apparatus not shown, in which the coil segments are inserted into slots, is placed on a carriage in a state that the workpiece72is placed on a pallet at the outside of the coil twisting apparatus15, and is passed to the pallet conveying guide41along with the pallet.

When the workpiece72is set to a predetermined position, the servomotor37rotates to raise the lifting table36. When the lifting table36reaches a predetermined position, the interlayer gap forming operation by the interlayer spacing member23is started.

When the interlayer gap forming operation is completed, the lifting table36is raised a predetermined distance so that, as shown by (a) inFIG.1, the segment end portions of the innermost segment layer12L1and the segment layer12L2adjacent thereto are inserted into the insertion grooves of the inner twisting jig50and the outer twisting jig51of the twisting jig unit28A, and the twist process described above is performed.

Next, the twist process is performed on a pair of adjacent segment layers12L3and12L4, and a pair of adjacent segment layers12L5and12L6, respectively. When the twist process is completed, the lifting table36is lowered, and the processed workpiece is taken out.

Next,FIG.12shows a configuration of a control unit configured to control the above coil twisting apparatus15. The coil twisting apparatus15may be configured such that an operator directly operates on-off and driving direction of each servomotor and the like by switches and the like, or that the processing procedure is programmed in advance and the above-mentioned process can be performed by an automatic control. Shown inFIG.12is a control unit for this automatic control.

A control unit shown inFIG.12at least has a function of controlling operations of various drive sources provided in the coil twisting apparatus15, that is, the inner servomotor26, the outer servomotor27, the servomotor37, a handling member drive source98configured to drive the handling members74, and the like, and has a CPU91, a non-volatile memory92, a RAM93, an operation unit I/F94, an operation unit95, a drive unit I/F96, a communication I/F97, and a system bus99.

The CPU91is a processor configured to control operations of various drive sources in accordance with the parameters stored in the non-volatile memory92and the operations by an operator performed on the operation unit95by executing programs stored in the non-volatile memory92using the RAM93as a work area.

The operation unit95is a unit configured to accept operations by an operator, such as a key, a button, a touch panel, or the like. The operation unit I/F94is configured to supply signals indicating operations performed on the operation unit95to the CPU91.

The driving unit I/F96is an interface configured to supply control signals to various drive sources in accordance with instructions from the CPU91.

The communication I/F97is an interface configured to communicate with external apparatuses.

The programs executed by the above-described CPU91include a program that defines the procedures of the above-described handling operation and twisting process. Parameters stored in the non-volatile memory92are: a raising amount of the workpiece72(lifting table36) for inserting the segment end portions into the twisting jigs for each twisting jig unit; a raising amount of the workpiece72and a rotating speed and a rotating amount of each twisting jig (twist characteristics) during the twisting process; a moving amount of the handling member74for the handling operation; and the like.

The CPU91instructs operations of the various drive sources to the drive unit I/F96in accordance with the above programs and parameters, thereby the coil twisting apparatus15automatically performs the above described processes such that the twist process including rotation of the inner twisting jig50and the outer twisting jig51while raising the workpiece72, and the handling operation by the interlayer spacing member23(each of the handling members74). The same automatic control is applicable to the second embodiment described below.

Next, the second embodiment will be described with reference toFIG.13toFIG.21. It should be noted that the same components as those in the above embodiment are denoted by the same reference numerals, and description of the above-described configurations and functions is omitted as appropriate.

As shown inFIG.13, a connection structure77A of coil segments in an electrical rotating machine according to the present embodiment is a structure wherein the segment end portions protruding from the end face of the core72aincludes: segment end portions12p1to12p6(first segment end portions) for connection, twisted in the circumferential direction of the core72a; and segment end portions12p1sand12p6s(second segment end portions) for power supply lines, extending in the axial direction of the core72a(not twisted), and wherein the segment end portions12p1sand12p6sfor power supply lines, opposing to each other in the radial direction of the core72a, are connected with each other via a terminal78as a conductor. It is not necessary that the segment end portions12p1sand12p6sfor power supply lines are at the exact same position in the circumferential direction, and they may be only close to each other with some gap in the circumferential direction.

The segment end portions12p1sand12p6sfor power supply lines as specific segment end portions are provided only in a predetermined layer or predetermined layers (here, the innermost segment layer12L1and the outermost segment layer12L6).

In either layer, the segment end portions12p1sand12p6sfor power supply lines are protruding longer from the end face of the core than the segment end portions12p1and12p6for connection provided in the same layer. Further, the segment end portions12p1sand12p6sare provided to replace some of the segment end portions12p1and12p6for connection.

The twisting in the present embodiment is basically the same as that in the first embodiment described above, but the twist process using a pushing member is performed on the innermost segment layer12L1and the outermost segment layer12L6.

That is, the twisting is performed such that the two segment end portions12p1sfor power supply lines in the innermost segment layer12L1remains not being twisted by the rotation of the twisting jig, and the two segment end portions12p6sfor power supply lines in the outermost segment layer12L6remain not being twisted by the rotation of the twisting jig.

A coil twisting method of allowing particular segment end portions to remain not being twisted is described below.

FIG.14shows a twisting jig unit28C used in this method, corresponding to the outermost segment layer12L6and the segment layer12L5on the inner side thereof, and the pushing member80. The inner twisting jig54of the twisting jig unit28C is provided with a plurality of insertion grooves (accommodating portions)54ato accommodate the segment end portions12p5for connection, of the segment layer12L5, and the outer sides of the insertion grooves54ain the radial direction are closed by the inner surface of the outer twisting jig55.

The outer twisting jig55is provided with a plurality of insertion grooves (accommodating portions)55ato accommodate the segment end portions12p6for connection, of the segment layer12L6, and the outer sides of the insertion grooves55ain the radial direction are closed by an outer ring55b

The pushing member80includes: an insertion frame81having an insertion groove81ato accommodate the segment end portions12p6sfor power supply lines as particular segment end portions existing in the outermost segment layer12L6; and a curved frame configured to close the inner side of the insertion groove81aof the insertion frame81in the radial direction and push the segment end portions12p6sfor power supply lines to positions where the segment end portions12p6sdo not interfere with the outer twisting jig55.

In this embodiment, when placing the workpiece72on the lifting table36of the coil twisting apparatus15for the twisting, the segment end portions12p1sand12p6sfor power supply lines are aligned to come to specific positions in the circumferential direction of the workpiece72. The pushing member80may be provided on the outer periphery of the outer ring55bin a range where the segment end portions12p1sand12p6sfor power supply lines come after the alignment. It is also possible to provide the pushing member80in a wider range in the circumferential direction to obtain a margin to some extent. InFIG.14andFIG.15, the left side in the drawing corresponds to this range, and the right side in the drawing does not correspond to this range.

Then, when raising the workpiece72while shifting slightly outward the segment end portions12p6sfor power supply lines as shown inFIG.14, the tip of the segment end portions12p6sfor power supply lines are guided by the curved frame82to enter the insertion groove81aas shown inFIG.15. As the workpiece72is raised further, the segment end portions12p6sfor power supply lines are pushed and bent along the shape of the curved frame82, pushed away to positions where the segment end portions12p6sdo not interfere with the outer twisting jig55, and held not to hinder the twist operation by the outer twisting jig55on the remaining segment end portions12p6for connection. The tip and the side surface of the curved frame82which contact with the segment end portions12p6sare preferably formed to be smoothly curved surfaces so that the segment end portions12p6sfor power supply lines can be pushed and bent without being scratched.

In the state ofFIG.15, the segment end portions12p5and12p6for connection are inserted into the insertion grooves54aand55a, respectively, and the twist process as in the case of the first embodiment can be performed by rotating the inner twisting jig54and the outer twisting jig55.

The pushing member80is fixed to the unit holder29separately from the twisting jig unit28C and holds the segment end portions12p6sfor power supply lines without rotating even during the rotation of the inner twisting jig54and the outer twisting jig55. The pushing member80may be fixed to any other fixing frame, not limited to the unit holder29.

Due to the above operation, as shown inFIG.16, only the segment end portions12p6for connection are twisted in the segment layer12L6, and the segment end portions12p6sfor power supply lines remain without being twisted because they are not inserted into the insertion grooves55aof the outer twisting jig55. That is, the segment end portions12p6sremain extended in the axial direction of the core72a.

Note that a process of displacing the segment end portions12p6sfor power supply lines outward can be performed using the interlayer spacing member23shown inFIG.10as a displacing member. Since the segment end portions12p6sfor power supply lines protrude longer from the end face of the core than the segment end portions12p6for connection, of the same layer, it is possible to displace the segment end portions12p6sfor power supply lines outward without affecting the segment end portions12p6for connection, by adjusting level in the vertical direction and position in the radial direction of each handling member74so that only the segment end portions12p6sfor power supply lines are respectively inserted into the insertion holes74c, and then moving each handling member74outward in the radial direction, similar to the case of the handling operation ofFIG.11AtoFIG.11C.

Further, even when the segment end portions12p6sfor power supply lines and the segment end portions12p6for connection, of the same layer, protrudes from the end face of the core by the same length before the twisting, it is possible to displace only the segment end portions12p6sfor power supply lines outward without affecting the segment end portions12p6for connection as in the case above, if the segment end portions12p6sprotrudes longer than the segment end portions for connection, of other layers, and an interlayer spacing member dedicated to the displacement process comprising handling members74only at positions in the circumferential direction where the segment end portions12p6sfor power supply lines are to be positioned is adopted.

For the innermost segment layer12L1, it is possible to twist only the segment end portions12p1for connection, and keep the segment end portions12p1sfor power supply lines without being twisted, i.e., extending in the axial direction of the core72a, as in the case above.

With respect to the segment layer12L1, a pushing member similar to the pushing member80may be provided on the inner peripheral side of the inner twisting jig50in the twisting jig unit28A corresponding to the segment layers12L1and12L2. Then, the segment end portions12p1sfor power supply lines can be displaced outward by pushing them using the interlayer spacing member23as a displacing member, and then pushed away to positions where the segment end portions12p1sfor power supply lines do not interfere with the inner twisting jig50.

Thus, as shown inFIG.17, only the segment end portions12p1for connection, of the innermost segment layer12L1, are twisted, and the segment end portions12p1sfor power supply lines remain without being twisted.

By keeping the segment end portions12p1sand12p6sfor power supply lines without being twisted, the segment end portions12p1sand12p6scan be opposed to each other in the radial direction of the core72aas shown inFIG.13, and thus a connection configuration of the power supply lines with the electrical connection via the terminal78along the shortest distance can be obtained. It is not necessary that the segment end portions12p1sand12p6sfor power supply lines are at the exact same position in the circumferential direction, and they may be only close to each other.

If the segment end portions for power supply lines were twisted in the same way as the segment end portions for connection, the segment end portions for power supply lines of the odd-numbered layer and those of the even-numbered layer are twisted in opposite directions and come to distant positions in the circumferential direction, and accordingly wiring configuration with a long conductor is necessary. However, according to the method and configuration of the present embodiment, the connection can be easily realized via the terminal78having a small area, and thus the connection configuration of the power supply lines can be extremely simplified. This simple configuration can also contribute to improvement of reliability.

However, if the segment end portions12p1sand12p6sfor power supply lines are expanded in the radial direction by the pushing member80not to interfere with the twisting jigs as shown inFIG.15, the segment end portions for power supply lines protrude inward in the radial direction in the innermost segment layer12L1and protrude outward in the radial direction in the outermost segment layer12L6. The inward protrusion in the innermost segment layer12L1narrows the inner diameter of the core72a, which may hinder the insertion operation of the rotor.

An example of addressing this point will be described with reference toFIG.18toFIG.20. As shown inFIG.18, a connection structure77B of coil segments according to the present embodiment is a structure wherein the segment end portions protruding from the end face of the core72aincludes: segment end portions12p1to12p6(short segment end portions) for connection twisted in the circumferential direction of the core72a; two segment end portions (first long segment end portions)12p1s′ for power supply lines in the innermost segment layer12L1(first layer), protruding longer than the segment end portions12p1for connection and twisted in the same direction as the segment end portions12p1for connection; and two segment end portions (second long segment end portions)12p6s′ for power supply lines in the outermost segment layer12L6(second layer), protruding longer than the segment end portions12p6for connection and twisted in a direction opposite to the twisting direction of the segment end portions12p6(short segment end portions) for connection.

The segment end portions12p1s′ for power supply lines and the segment end portions12p6s′ for power supply lines opposing thereto are electrically connected via the terminal78. The segment end portions12p1to12p6for connection of each layer are twisted in opposite directions alternately layer by layer.

In the twisting in the present embodiment, regarding the innermost segment layer12L1, the segment end portions12p1for connection and the segment end portions12p1s′ for power supply lines are simultaneously twisted in the same direction as shown inFIG.19, using an inner twisting jig (first twisting jig) having accommodating portions (here, insertion grooves) configured to accept insertion of the segment end portions12p1for connection and accommodating portions configured to accept insertion of the long segment end portions12p1s′ for power supply lines. At this time, the segment end portions12p1s′ for power supply lines are not pushed to a position where they do not interfere with the inner twisting jig. Therefore, the segment end portions12p1s′ for power supply lines do not protrude to the inner side in the radial direction.

Incidentally, the depth of each accommodating portion may be all the same as long as the long segment end portions12p1s′ for power supply lines can be accommodated therein. Alternatively, if the workpiece72is arranged such that the segment end portions12p1s′ for power supply lines come to specific positions in the circumferential direction, the depth of the accommodating portions configured to accommodate the segment end portions12p1s′ for power supply lines may be deeper than the depth of the accommodating portions configured to accommodate the segment end portions12p1for connection. In any case, the part of each segment end portion which is inserted into the accommodating portion remains straight after the twist process.

Further, the inner twisting jig described here can be used in place of the inner twisting jig50of the twisting jig unit28A.

On the other hand, regarding the outermost segment layer12L6, the segment end portions12p6s′ for power supply lines are pushed away to positions where they do not interfere with the outer twisting jig51(second twisting jig) and then only the segment end portions12p6for connection are twisted first, using the pushing member80and the twisting jig unit28C as described inFIG.14andFIG.15. Thereafter, as shown inFIG.20, only the segment end portions12p6s′ for power supply lines which remain without being twisted, are twisted in a direction opposite to the twisting direction of the segment end portions12p6for connection (in the same direction as the segment end portions12p1s′ for power supply lines) so that the segment end portions12p6′ oppose to the segment end portions12p1s′ for power supply lines, using another twisting jig (third twisting jig).

In this way, it is possible to form a simple connection configuration of power supply lines without narrowing the inner diameter of the core72a.

Although the present embodiment adopts the configuration of pushing the segment end portions for power supply lines remaining without being twisted away to positions where they do not interfere with the twisting jig by the pushing member80, as shown inFIG.21, the segment end portions12p6sor12p6s′ for power supply lines may be pushed to positions where they do not interfere with the twisting jig by using the interlayer spacing member23described in the first embodiment. That is, the interlayer spacing member23may be used as a displacing member. When pushing the segment end portions12p1sor12p1s′ for power supply lines in the innermost segment layer12L1, the segment end portions may be pressed to the center side of the core by the interlayer spacing member23. On the contrary, a member other than the interlayer spacing member23may be used as the above-mentioned displacing member.

Further, the shapes of the twisting jigs may be changed so that the twisting jigs themselves have the function of the pushing member80.

Further, in the above-described embodiment, it has been described that the segment end portions12p1sand12p6sfor power supply lines are aligned when the pushing member80is used. However, this is not essential. If the segment end portions12p1sand12p6sfor power supply lines projects longer from the end face of the core than the segment end portions12p1and12p6for connection, of the same layer, it is possible to displace the segment end portions12p1sand12p6sfor power supply lines by some of the handling members74, regardless of the circumferential position of the segment end portions12p1sand12p6s. Then, if the pushing member80is provided on the entire periphery of the outer ring55b, the segment end portions12p1sand12p6sfor power supply lines can be pushed to a position where they do not interfere with the twisting jig regardless of the circumferential positions thereof.

Further, in the above embodiment, an example of a stator as the work has been described, but rotors can also be implemented in the same manner.

Preferred embodiments of the present invention are described above. However, the present invention is not limited to such specific embodiments, and various modifications and variations are conceivable. The above-described configuration of the present invention can be implemented by extracting only a part thereof, and the variations described in the above explanation can be applied in any combination as long as they do not conflict with each other. The effects described in the embodiments of the present invention are merely illustrative of the most preferred effects resulting from the present invention, and the effects according to the present invention are not limited to those described in the embodiments of the present invention.

REFERENCE SIGNS LIST