JP4539418B2 - Method of joining segment coil ends - Google Patents

Description

  The present invention relates to a method for joining coil ends after twisting a segment coil inserted into a slot of a stator core. More specifically, the present invention relates to a method for joining segment coil ends that can improve the productivity of a stator.

  In a segment type coil motor, after inserting a segment coil into a slot provided in the stator core, the tip of the segment coil is twisted, and the ends thereof are joined (welded) to manufacture the stator. Here, as shown in FIG. 15, the segment coil tip portions 103 and 104 to be joined before joining (after twisting) are arranged in a radial pattern, and the total number thereof is as large as several hundred. For example, in FIG. 15, the total number of tips of the segment coils 103 and 104 is “576”. And among the segment coils arranged in this way, adjacent ones are joined in pairs (joined by TIG welding or laser welding). For this reason, as shown in FIG. 16, the junction points 105 are also arranged radially, and the total number thereof is as large as several hundreds. For example, in FIG. 16, the total number of junction points 105 is “288”.

  And since the joining of the segment coil ends is performed at each joining point 105 (one by one) by TIG welding, laser welding, or the like, it is necessary to perform several hundreds of weldings until all the ends are joined. It took a very long time. That is, the above joining method has a problem of low productivity.

  Therefore, a technique for shortening the joining time of the segment coil end has been proposed. As one of them, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 2001-275288. In the technique disclosed here, a rod conductor is disposed in a slot of a stator core, and an end portion of the rod conductor and a plurality of end plates in which the conductor is resin-molded are joined.

JP 2001-275288 A

  However, in the above-described prior art, it is possible to shorten the joining time of the segment coil ends than to weld the joining points one by one, but there is a limit to shortening the coil end height. This is because it is necessary to arrange a plurality of end plates in the stator axial direction.

  As one of the requirements for a drive motor for a hybrid vehicle, there is a reduction in the size of the motor, particularly a reduction in the axial length of the motor due to the mounting space. That is, it is necessary to shorten the coil end height in the stator as much as possible.

  Therefore, the present invention has been made to solve the above-described problems, and a method for joining segment coil ends that can shorten the joining time between the segment coil ends and shorten the coil end height. It is an issue to provide.

  The segment coil end joining method according to the present invention made to solve the above problems is a segment coil end joining method in which the end of a segment coil inserted into a slot of a stator core and twisted is joined. Other than the segment coils respectively arranged on the outermost and innermost circumferences of the stator, the side surfaces of a pair of segment coils to be joined, and the outermost circumferences arranged on the outermost and innermost circumferences of the stator, respectively. A conductive adhesive is applied to each end face of the segment coil and the innermost peripheral segment coil, and the crossover conductor for joining the ends of the outermost peripheral segment coil and the innermost peripheral segment coil leaves the joint. In the embedded resin member, the joint and the end portions of the outermost segment coil and the innermost segment coil coincide with each other. And pressurizing the resin member against the ends of the outermost segment coil and the innermost segment coil so that the end side surfaces of the segment coils to be joined are close to each other. Then, the conductive adhesive is cured.

In this method of joining the segment coil ends, first, the end side surfaces of a pair of segment coils other than the segment coils respectively arranged on the outermost and innermost circumferences of the stator and to be joined, the outermost circumference of the stator and A conductive adhesive is applied to each end face of the outermost peripheral segment coil and the innermost peripheral segment coil arranged on the innermost periphery, respectively. Specifically, for example, a conductive adhesive is applied to the side surfaces and end portions of the segment coil using a fine nozzle. And about 15-20 mg of conductive adhesive should just be apply | coated with respect to one junction part (about 5-10 mm < ² >).

  Next, the resin member in which the crossover conductor for joining the end portions of the outermost segment coil and the innermost segment coil is embedded leaving the joint portion, the joint portion, the outermost segment coil, and the innermost segment coil It arrange | positions so that the edge part of may correspond. Then, the resin member is pressed against the end portions of the outermost segment coil and the innermost segment coil, and the conductive adhesive is cured by pressing so that the end side surfaces of the segment coils to be joined are close to each other. Let Here, the applied pressure may be about 50 to 100 kPa, and the curing time may be about 20 to 40 minutes (about 100 to 200 ° C.).

  Thus, in this joining method, since the segment coil end portions for one row in the stator radial direction can be joined at a time, the joining time can be shortened. Moreover, since what is arrange | positioned at the segment coil edge part (stator axial direction) is one resin member with which only the transition part conductor was embedded, coil end height can be shortened. That is, the joining time can be shortened and the coil end height can be shortened.

  In the method for joining segment coil ends according to the present invention, the resin member is inserted between the pair of segment coils to be joined, and the pair of segment coils to be joined are brought close to each other and pressurized. It is desirable that a bonding pressure member is formed. And it is desirable that the joining pressure member has a wedge shape. The pressure bonding member needs to be formed of an insulating material.

  By carrying out like this, by arrange | positioning and pressurizing a resin member in a predetermined position, a joining pressure member is inserted between a pair of segment coils used as joining object, and it pressurizes in the direction in which the pair of segment coils adjoin. Because it can. And by making it a wedge shape, the force (pressing force) for making a pair of segment coils adjoin and pressurize increases / decreases in proportion to the insertion depth of a joining pressurization member. For this reason, the applied pressure can be optimally adjusted by changing the shape of the wedge.

  Moreover, in the joining method of the segment coil end part which concerns on this invention, it is desirable for the said resin member to be formed in the disk shape by embedding a some transition part conductor.

  By doing so, it is possible to join not only one row in the stator radial direction but the entire circumference, that is, all the end portions of the segment coils arranged in the stator core at a time. Therefore, the bonding time can be further shortened by embedding a plurality of crossover conductors in the resin member in a disk shape.

Here, as the twist forming performed before joining the segment coil end portions, the load point of the load acting on the segment coil from the twist jig near the center of the segment coil end portion protruding from the stator core. Then, it is desirable to twist the segment coil by relatively moving the twisting jig and the segment coil so that the load point is continuously moved toward the tip of the segment coil.
This is because the coil end height can be shortened by performing such twist forming. That is, after performing such twist forming, the coil end height can be shortened more efficiently by joining the end portions of the segment coils by the joining method described above.

  Here, in order to continuously move the load point toward the tip of the segment coil, the twist jig and the segment coil are moved away from each other while rotating the twist jig and the segment coil relatively in the circumferential direction. You can do it.

  According to the method for joining segment coil ends according to the present invention, as described above, the joining time between the segment coil ends can be shortened and the coil end height can be shortened.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. In the present embodiment, a case will be described in which the present invention is applied to manufacture of a stator used for a drive motor of a hybrid vehicle.
First, twist forming performed before joining the segment coil ends will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a part of a twisted ring. FIG. 2 is an explanatory view showing a state in which the segment coil end portion is accommodated in the coil end accommodating portion of the twisted ring. FIG. 3 is an explanatory view showing a state when twist forming is started. FIG. 4 is an explanatory view showing a state in which twisting is performed by lowering and rotating the twisting ring. FIG. 5 is an explanatory diagram showing a state at the time when the lowering of the twisted ring is finished. FIG. 6 is a diagram showing a state in which twisting is performed by rotating and rotating the twisting ring.

  The twisting of the segment coil is performed by the twisted ring 2 having the coil end accommodating portion 21. As shown in FIG. 1, the coil end accommodating portion 21 has an elongated hole shape and is formed at a predetermined interval in the circumferential direction. The depth D of the coil end accommodating portion 21 is set to be at least 1/12 times the diameter of the stator core 10 so that more than half of the segment coils 11 protruding from the stator core 10 can be accommodated from the tip. Further, the width dimension W of the coil end accommodating portion 21 is set to 1.5 times or more the width dimension in the circumferential direction of the segment coil 11. As a result, when positioning is performed by bringing the end side surface of the segment coil 11 into contact with the rotation direction rear surface 21D of the coil end accommodating portion 21, the position between the bottom surface 21E and the tip of the segment coil 11, and the rotation direction front surface 21F. Between the segment coils 11 and the segment coils 11, about half of the segment coils 11 protruding from the stator core 10 from the tip can be accommodated in the coil end accommodating portion 21. In the present embodiment, a substantially U-shaped segment coil 11 is used. For this reason, the twist forming of the segment coil 11 and the joining of the coil ends are performed only at the coil end on one end side.

  Further, a chamfered portion 21G is formed at the stator core side end portion of the rotational direction rear surface 21D of the coil end accommodating portion 21. Thereby, insertion of the edge part of the segment coil 11 to the coil edge accommodating part 21 can be performed smoothly. For these reasons, even if the dimensions of the segment coil 11 vary, the segment coil 11 can be reliably inserted into the coil end accommodating portion 21 without riding on the twisted ring 2 or being deformed. ing.

  Here, in this embodiment, 12 segment coils are provided in the stator radial direction. For this reason, it is extremely difficult to twist all the segment coil ends at once because the ends are in a narrow range. Therefore, it is divided into several times (for example, 4 pieces (4 rows)). Since the twist forming method for each time is the same, the twist forming method for one time will be described below.

  First, as shown in FIG. 2, the end portion of the segment coil 11 is accommodated in the coil end accommodating portion 21 of the twisted ring 2. Then, as shown in FIG. 3, the twisting ring 2 is rotated and twisting is started. At this time, the load point of twist forming (boundary portion between the rear surface 21D in the rotation direction and the chamfered portion 21G) is located near the end surface of the stator core 10 instead of the tip of the segment coil 11. More specifically, a twist forming load point is located about half of the segment coil 11 protruding from the end face of the stator core 10 from the tip. For this reason, the segment coil 11 is reliably bent near the end face of the stator core 10.

  Thereafter, as shown in FIG. 4, the twisting ring 2 is lowered while being rotated, and twisting is performed. At this time, the operation of the twisted ring 2 is controlled so that the segment coil 11 does not contact the front surface 21F in the rotation direction of the coil end accommodating portion 21. Thereby, the load point of twist forming gradually moves toward the tip of the segment coil 11.

  And as shown in FIG. 5, when the front-end | tip of the segment coil 11 is located in the chamfer 21G, the downward motion of the twisting ring 2 is stopped. Thereafter, in order to shorten the coil end height, the twisted ring 2 is raised as shown in FIG. At this time, the torsion ring 2 is rotated.

  In this way, by using the twisted ring 2, the load point of twist forming at the start of twist forming is positioned at about half of the segment coil 11 protruding from the end face of the stator core 10, and then the load The point is gradually moved toward the tip of the segment coil 11. As a result, the segment coil 11 inserted into the stator core 10 is twisted linearly (without bending), and the coil end portion is in a state as shown in FIG. FIG. 7 is an explanatory view showing a state of the coil end portion after twist forming. After the twist forming, as shown in FIG. 7, the joined portions of the segment coils 11 are arranged in a line in the stator radial direction.

  And the segment coil end portion twisted as described above does not have a straight line portion extending in the stator axial direction. Here, the straight line portion is necessary for grounding when joining by welding, and in the technique of Patent Document 1, a plurality of end plates are arranged to each end plate and each bar conductor. It was necessary for joining. On the other hand, as will be described later, in the joining method according to the present embodiment, the end portions of the segment coils can be joined without forming such a linear portion. Thereby, in the joining method according to the present embodiment, the coil end height can be shortened because there is no need to form a linear portion in the twist forming performed before joining.

  Next, a method for joining the segment coil ends will be described with reference to FIGS. FIG. 8 is an explanatory view showing a state in which a dispenser is arranged above a pair of segment coils to be joined. FIG. 9 is an explanatory view showing a state where the nozzle of the dispenser is inserted between a pair of segment coils to be joined. FIG. 10 is an explanatory view showing a state in which the application of the conductive adhesive between the pair of segment coils to be joined is completed.

  First, a conductive adhesive (Ag weight content 80% in this embodiment) 45 is applied to the end of the segment coil 11 to be joined. Specifically, the conductive adhesive 45 is applied to the end of the segment coil 11 using a dispenser 40 as shown in FIG. A nozzle 41 having pores is attached to the dispenser 40, and the conductive adhesive 45 can be discharged from the nozzle 41. And with respect to the innermost periphery segment coil 11i and the outermost periphery coil 11o, the conductive adhesive 45 is apply | coated to each coil front-end | tip part by the dispenser 40 (refer FIG. 11). Moreover, with respect to the segment coils 11 other than the innermost peripheral segment coil 11i and the outermost peripheral coil 11o, a conductive adhesive is applied to the side surfaces of the coil ends by a dispenser 40 between a pair of segment coils 11 and 11 to be connected. Agent 45 is applied. Specifically, as shown in FIG. 9, the dispenser 40 is lowered and the nozzle 41 is inserted between the segment coils 11 and 11 to start discharging the conductive adhesive 45. Almost simultaneously with the start of discharging the conductive adhesive 45 from the nozzle 41, the dispenser 40 is raised as shown in FIG. Thus, a predetermined amount (15 to 20 mg) of the conductive adhesive 45 can be applied to the end side surface of the segment coil 11. 8 to 10 exemplify the case where the conductive adhesive 45 is applied to only one place, the conductive adhesive 45 may be applied to all five places at once. Thereby, the time to apply the conductive adhesive 45 can be shortened.

  When the conductive adhesive 45 has been applied to all the joints, the annular resin plate 30 shown in FIG. 7 is disposed above the stator core 10. As shown in FIG. 11, a bridging portion conductor 31 for connecting the innermost peripheral segment coil 11 i and the outermost peripheral segment coil 11 o is embedded in the resin plate 30. FIG. 11 is a cross-sectional view showing a schematic configuration of a resin plate. The crossover conductor 31 is formed in a U-shaped cross section, and the joining surfaces 12, 12 joined to the innermost segment coil 11 i and the outermost segment coil 11 o are exposed from the resin plate 30. In the present embodiment, 48 crossover conductors 31 are embedded in the resin plate 30.

  In addition, the resin plate 30 includes a plurality of wedge-shaped protrusions 32 below the crossover conductor 31 (on the side joined to the segment coil). In the present embodiment, since five wedge-shaped projections 32 are provided for one jumper portion conductor 31, a total of 240 (= 5 × 48) wedge-shaped projections 32 are provided on the resin plate 30. It will be provided. These wedge-shaped projections 32 are used to apply pressure so that the pair of segment coils 11 and 11 to be joined are brought close to each other when the resin plate 30 is attached to the end of the segment coil 11 and held under pressure. Is.

  The shape of the wedge-shaped protrusion 32 is such that when the resin plate 30 is attached to the end of the segment coil 11 and held at a pressure of about 50 to 100 kPa, the pair of segment coils 11 and 11 to be joined are brought close to each other. It is formed so that a pressurizing force of the same level (50 to 100 kPa) is generated. In addition, the wedge-shaped protrusion 32 is formed of an insulating material (for example, resin) in order to insulate a pair of adjacent segment coils.

  As shown in FIG. 12 or 13, such a resin plate 30 is brought into contact with the end of the segment coil 11 and pressurized. FIG. 12 is a cross-sectional view for explaining a state where the resin plate and the segment coil are in contact with each other. FIG. 13 is a perspective view showing a state of the transition conductor and the wedge-shaped protrusion in a state where the resin plate and the segment coil are in contact with each other.

At this time, as shown in FIG. 12, the joining surfaces 12 and 12 of the crossover conductor 31 are in contact with the innermost peripheral segment coil 11 i and the outermost peripheral segment coil 11 o via the conductive adhesive 45. In addition, each wedge-shaped protrusion 32 enters between the pair of segment coils 11 and 11 to be joined. Thereby, a pair of segment coil 11 and 11 used as joining object are pressurized in the direction which mutually adjoins.
Here, only the segment coils for one row in the stator radial direction are shown, but when the resin plate 30 is brought into contact with the end of the segment coil 11 and pressed, the segment coils for all 48 rows attached to the stator core 10 are shown. The state shown in FIG. 12 is obtained at the end.

  Then, the conductive adhesive 45 is cured by maintaining the pressurized state for about 30 minutes in an environment of about 150 ° C. with the resin plate 30 attached to the end of the segment coil. This completes the joining of the segment coil ends. Here, paying attention to the joining portion, as shown in FIG. 14, the segment coils 11 and 11 are joined to each other via the conductive adhesive 45. FIG. 14 is an enlarged view schematically showing a joint portion between the segment coils 11 and 11. And the wedge-shaped protrusion 32 exists in the segment coil edge part side surface. For this reason, since the segment coils 11 and 11 are always receiving force from the wedge-shaped projections 32 in a direction in which they are close to each other, they are joined with sufficient mechanical strength. Further, the joint portion is also electrically connected through the conductive adhesive 45, and a necessary and sufficient current I can flow.

  That is, in the joining method according to the present embodiment, joining performance equivalent to that when joining by TIG welding or laser welding can be ensured. And compared with TIG welding and laser welding, a segment coil edge part can be joined in a short time. Further, since the end portions of the segment coils can be joined by the single resin plate 30, the coil end height can also be shortened. Furthermore, in the resin plate 30, since only the crossover conductor 31 is molded, the resin plate itself is also thin, so that the coil end height can be shortened accordingly. In particular, a stator used in a motor for driving a hybrid vehicle is required to shorten the coil end height in millimeters. Therefore, the coil end height is reduced by several millimeters as the resin plate itself is thinned (several millimeters). ) Is a big effect.

  As described above in detail, according to the method for joining the segment coil ends according to the present embodiment, the side surfaces of the pair of segment coils 11, 11 to be joined, the outermost segment coil 11o, and the innermost segment A conductive adhesive 45 is applied to each end face of the peripheral segment coil 11i to connect the resin plate 30 in which the crossover conductor 31 is embedded and the wedge-shaped projection 32 is formed, and the joint portion 12 of the crossover conductor 31 is It arrange | positions so that it may correspond to each edge part of the outermost periphery segment coil 11o and the innermost periphery segment coil 11i. Then, the state in which the resin plate 30 is pressed with a predetermined pressure is maintained for a predetermined time to cure the conductive adhesive 45 and join the end portions of the segment coils.

  For this reason, in the method for joining segment coil ends according to the present embodiment, all the segment coil ends can be joined at once by placing the resin plate 30 at a predetermined position, thereby shortening the joining time. can do. Further, since only the thin resin plate 30 in which only the crossover conductor 31 is embedded is arranged at the end of the segment coil (in the stator axial direction), the coil end height can be shortened. That is, according to the joining method of the segment coil end part according to the present embodiment, the joining time can be shortened and the coil end height can be shortened.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. In the above-described embodiment, a substantially U-shaped segment coil 11 is used, but a rod-shaped one can also be used. When a rod-shaped segment coil is used, twist forming and coil end connection may be performed at both ends of the coil end.

  Further, in the above-described embodiment, the case where the present invention is applied to the manufacture of the stator used for the drive motor of the hybrid vehicle is illustrated, but the present invention is limited to the manufacture of the stator used for the vehicle motor. In addition, the present invention can be applied to manufacture of a stator used in a motor for any application using a segment coil.

It is sectional drawing which shows a part of twisted ring. It is explanatory drawing which shows the state which accommodated the segment coil end part in the coil end accommodating part of the twisted ring. It is explanatory drawing which shows a state when twist forming is started. It is explanatory drawing which shows the state which is rotating while lowering a twisting ring and performing twist forming. It is explanatory drawing which shows the state at the time of the fall of a twisting ring complete | finished. It is a figure which shows the state which is rotating while raising a twisting ring and performing twist forming. It is explanatory drawing which shows the state of the coil end part after twist forming. It is explanatory drawing which shows the state which has arrange | positioned the dispenser above a pair of segment coil which is a joining object. It is explanatory drawing which shows the state which inserted the nozzle of the dispenser between a pair of segment coils which are joining objects. It is explanatory drawing which shows the state which complete | finished application | coating of the conductive adhesive between a pair of segment coils which are joining objects. It is sectional drawing which shows schematic structure of a resin board. It is sectional drawing for demonstrating the state which the resin plate and the segment coil contacted. It is a perspective view which shows the state of a transition part conductor and a wedge-shaped protrusion in the state which the resin plate and the segment coil contacted. It is an enlarged view which shows typically the junction part of segment coils. It is a schematic diagram which shows typically the segment coil front-end | tip part after twist forming. It is a schematic diagram which shows a junction point typically.

Explanation of symbols

2 Twisted ring 10 Stator core 11 Segment coil 11i Innermost peripheral segment coil 11o Outermost peripheral segment coil 30 Resin plate 31 Transition portion conductor 32 Wedge-like projection 40 Dispenser 41 Nozzle 45 Conductive adhesive

Claims (4)

In the joining method of the segment coil end part, which joins the end part of the segment coil inserted into the slot of the stator core and twisted,
Other than the segment coils respectively arranged on the outermost and innermost circumferences of the stator, the side surfaces of a pair of segment coils to be joined, and the outermost circumferences arranged on the outermost and innermost circumferences of the stator, respectively. Apply conductive adhesive to each end face of the segment coil and innermost segment coil,
A resin member in which a crossover conductor for joining the end portions of the outermost peripheral segment coil and the innermost peripheral segment coil is embedded leaving the joint portion, the joint portion, the outermost peripheral segment coil, and the innermost peripheral segment. Arrange so that each end of the coil matches,
The resin member is pressed against the ends of the outermost segment coil and the innermost segment coil, and the side surfaces of the segment coils to be joined are pressed so as to be close to each other, and the conductive bonding is performed. A method for joining segment coil ends, wherein the agent is cured. In the joining method of the segment coil end part of Claim 1,
The resin member is formed with a bonding pressure member that is inserted between the pair of segment coils to be bonded and pressurizes the pair of segment coils to be bonded in proximity to each other. Method of joining segment coil ends. In the joining method of the segment coil end part described in claim 2,
The method for joining segment coil ends, wherein the joining pressure member has a wedge shape. In the joining method of any one segment coil end part described in Claims 1-3,
The method of joining segment coil ends, wherein the resin member is formed in a disk shape by embedding a plurality of crossover conductors.

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