JP2009095193A - Stator of motor and method of manufacturing coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator of a motor, for which a coil end portion is shortened, and also to provide a method of manufacturing a coil. <P>SOLUTION: The stator 10 of a motor comprises a stator core 11 formed by stacking steel plates and a coil 12 disposed in the stator core 11. First to eleventh U-shaped conductors 121-131 which are formed in a U-shape by plastic working, are stacked on each other to form first conductors 12a to be inserted from the top face side, first conductors 12b to be inserted from the bottom face side, second conductors 12c to be inserted from the top face side, and second conductors 12d to be inserted from the bottom face side, each constituting part of the coil 12. The conductors 12a, 12b, 12c, and 12d are inserted into slots 11a of the stator core 11, with the end faces of the conductors 12a and 12b joined together and the end faces of the conductors 12c and 12d joined together, forming the shape of a coil. Thus, the conductors 12a, 12b, 12c, and 12d are disposed in the shape of a coil in the stator core 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a technique for forming a coil used for a stator, and more specifically, a method for forming a coil by resistance welding a conductor in a slot.

Among motors used in automobiles, a large current flows particularly in a driving motor used in a hybrid car. This is because it is necessary to generate a large force for use as a driving force of an automobile.
Therefore, a large current flows through the coil used for the stator of the motor. If the resistance of the coil is high, a large amount of heat is generated, which is a problem.
This is because, in addition to losing electric power by passing current and changing to heat, there is a risk of shortening the life of the resin that molds the surroundings by the heat generated by itself, the substrate used nearby, etc. .

Therefore, it is necessary to reduce the resistance of the coil and suppress heat generation.
In recent years, demands for motors have increased, and miniaturization and high output have been demanded.
For this reason, a method of winding a flat wire or a method of welding a flat wire at an end instead of forming a coil by winding is being sought.

Patent Document 1 discloses a technique related to a method for manufacturing a rotor of a rotating electrical machine. When joining the substantially U-shaped coil conductors used in the rotor, the joint is bent outward and welded using a welding torch. At that time, the surroundings are cooled using a cooling jig. ing.
Patent Document 2 discloses a technique related to a welding positioning jig and a coil forming method. This is a method of forming a coil called a segment coil by twisting the end of a U-shaped flat member called a conductor segment and welding the end. The end is welded using arc welding or the like. ing.

  Patent Document 3 discloses a technique related to a segment coil welding method and a ground jig. After inserting the U-shaped conductor segment into the stator core, twist the end, contact the probe of the earth jig on the opposite lead side, that is, the U-shape side of the conductor segment, and form the coil by arc welding It is a method to do.

JP-A-8-331813 JP 2003-134754 A JP 2004-328861 A

However, when forming a coil using the techniques disclosed in Patent Documents 1 to 3, it is considered that there are the following problems.
In all of the techniques disclosed in Patent Documents 1 to 3, coils are formed by welding. Therefore, it is necessary to provide a welding wire at the coil end portion, which inevitably increases the coil end.
Motors are required to be further miniaturized, and shortening of the coil end part is also an issue. In the case of using welding, a welding wire is inevitably required because of melting and joining the conductors, and the coil end portion becomes large.
Further, as described in Patent Document 2 and Patent Document 3, when a rectangular coil is bent into a U-shape to form a segment coil, a minimum bending radius is required for the width of the rectangular conductor, and therefore the anti-lead side side is required. The coil end portion also tends to be large.

  Accordingly, an object of the present invention is to provide a motor stator and a coil manufacturing method capable of shortening the coil end portion in order to solve such problems.

In order to achieve the above object, the stator of the motor according to the present invention has the following characteristics.
(1) In a stator of a motor comprising a stator core formed by stacking steel plates, and a coil disposed on the stator core,
A plurality of conductors formed in a substantially U shape by plastic working are stacked, and a first conductor forming a part of the coil and a second conductor forming a part of the coil are formed on the stator core. Inside the formed slot portion, the end surfaces of the first conductor and the second conductor are joined together to form a coil shape, which is disposed on the stator core.

(2) In the motor stator described in (1),
A ceramic insulating sleeve is inserted into the slot portion formed in the stator core, the first conductor and the second conductor are inserted into the insulating sleeve, and end faces are joined to each other. And

(3) In the stator of the motor according to (1) or (2),
The first conductor and the second conductor are upset welded by pressurizing the first conductor and the second conductor and passing a current.

(4) In the stator of the motor described in (2) or (3),
The end portion of the insulating sleeve that becomes the outer peripheral side when inserted into the stator core is formed in a semicircular shape, and the first conductor and the second conductor inserted into the insulating sleeve also correspond to a semicircular shape. It is characterized by being formed.

(5) In the stator of the motor described in any one of (1) to (4),
The end surface of the first conductor and the end surface of the second conductor are formed in a step shape.

In order to achieve the above object, the coil manufacturing method according to the present invention has the following characteristics.
(6) In a coil manufacturing method for forming a coil shape by inserting a conductor forming a part of a coil into a stator core formed by laminating steel plates and joining the conductors,
The conductor is formed in a substantially U-shape by plastic working, a plurality of the conductors are overlapped, a first conductor inserted from one surface of the stator core, a plurality of the conductors are overlapped, and the other of the stator cores A second conductor inserted from the surface of the stator core, and the first conductor is inserted into a slot formed in the stator core from one surface side of the stator core, and the second conductor is inserted into the other side of the stator core. The coil shape is formed by inserting from the surface side and bringing the end face of the first conductor inserted into the stator core into contact with the end face of the second conductor and joining them.

(7) In the coil manufacturing method according to (6),
The first conductor and the second conductor are upset welded by applying pressure and applying current to the first conductor and the second conductor.

(8) In the coil manufacturing method according to (6) or (7),
An insulating sleeve made of ceramic is inserted into the slot portion formed in the stator core, the first conductor and the second conductor are inserted into the insulating sleeve, and end faces are joined to each other. And

The following actions and effects can be obtained by the stator of the motor according to the present invention having such characteristics.
First, the invention described in (1) is formed in a substantially U-shape by plastic working in a stator of a motor including a stator core formed by stacking steel plates and a coil disposed on the stator core. A first conductor forming a part of the coil and a second conductor forming a part of the coil are formed, and the first conductor and the second conductor are formed inside the slot portion formed in the stator core. The end surfaces of the two conductors are joined together to form a coil shape, which is arranged on the stator core.
The first conductor and the second conductor do not have a joining portion at the coil end, and are joined inside the stator core, so that it is not necessary to provide a welding solder or the like at the coil end portion of the stator.
In addition, the shape of the coil end can be optimized by forming the first conductor and the second conductor by plastic working. Therefore, the coil end portion can be shortened to form a coil.

For example, as in Patent Document 2 and Patent Document 3, when welding a rectangular conductor bent in a U shape at the coil end, it is necessary to provide a welding wire on the welding side as described in the problem, Requires a space for ensuring a minimum bending radius R of the conductor. However, the first conductor and the second conductor are plastically processed into a substantially U-shape and joined inside the stator core, so that the first conductor and the second conductor exposed in the coil end portion have arbitrary shapes. It will be good. That is, it is possible to optimize the coil end to be the shortest.
Therefore, it is possible to provide a motor stator capable of shortening the coil end portion, which contributes to miniaturization of the motor.

The invention described in (2) is the motor stator described in (1), wherein an insulating sleeve made of ceramic is inserted into a slot formed in the stator core, and the first conductor and The second conductor is inserted and the end faces are joined together.
Since the end portions of the first conductor and the second conductor are resistance-welded, it is considered that the temperature is considerably high during welding. Therefore, when a resin-based insulating material is used, there is a possibility that the insulating portion melts and insulation cannot be secured. That is, in order to ensure insulation between the stator core and the coil, it is necessary to use an insulating material having high heat resistance.
Therefore, a ceramic insulating sleeve is used, and the first conductor and the second conductor are inserted therein.
Ceramic insulating sleeves have insulation and heat resistance and can withstand the heat generated during resistance welding. For this reason, insulation is ensured, and reduction of defects during coil manufacturing can be expected.

Further, the invention described in (3) is the motor stator described in (1) or (2), wherein the first conductor and the second conductor are pressurized and an electric current is passed in the stator of the motor. Since the second conductor is upset welded, the mechanical strength of the welded portion can be obtained.
Upset welding is a type of resistance welding, and by flowing an electric current while applying pressure, heat can be generated at the contact portion to join the first conductor and the second conductor. Since the end portions of the first conductor and the second conductor have a relatively small cross-sectional area and a mechanical strength is obtained, upset welding in which current is applied while welding and welding is suitable.

Further, in the invention described in (4), in the motor stator described in (2) or (3), the end portion of the insulating sleeve that becomes the outer peripheral side when inserted into the stator core has a semicircular shape. The first conductor and the second conductor inserted into the insulating sleeve are also formed in a semicircular shape correspondingly.
Eddy currents are generated in the laminated steel plates constituting the stator core when current is supplied to the coil as a stator. Further, in view of punching the steel plate with a press or the like, it is convenient that the shape of the slot portion of the stator core is semicircular on the outer peripheral side of the stator core. For this reason, it is more convenient for the shape of the insulating sleeve inserted into the slot portion to be formed in a semicircular shape correspondingly.
And the outer peripheral part to which a 1st conductor and a 2nd conductor respond | correspond is also formed in a semicircle shape, and it becomes possible to improve the space factor of a stator.

The invention described in (5) is the motor stator described in any one of (1) to (4), wherein the end surface of the first conductor and the end surface of the second conductor are stepped. Since it is formed, it becomes easy to confirm whether or not the joint is properly joined.
The end portions of the first conductor and the second conductor are abutted and joined inside the stator core. Therefore, for example, a method of confirming the joint portion by transmitting with X-rays can be considered, but since the conductor is thin, it is possible to determine which portion is defective even if a specific defect is seen. Hateful.
However, since the end surfaces of the first conductor and the second conductor are formed in a stepped shape, this defect can be easily identified by the height. If it becomes easy to specify the position of the bonding failure, it is possible to contribute to the investigation of the cause.

Moreover, the following operations and effects can be obtained by the coil manufacturing method according to the present invention having such characteristics.
The invention described in the above (6) is a coil manufacturing method for forming a coil shape by inserting a conductor forming a part of a coil into a stator core formed by laminating steel plates, and joining the conductors. The conductor is formed into a substantially U shape by plastic working, and a plurality of conductors are overlapped, the first conductor inserted from one surface of the stator core, and the plurality of conductors are overlapped, and inserted from the other surface of the stator core. A second conductor is inserted into the slot formed in the stator core, the first conductor is inserted from one side of the stator core, and the second conductor is inserted from the other side of the stator core. In addition, the end face of the first conductor and the end face of the second conductor are brought into contact with each other and joined to form a coil shape.
Therefore, the connecting portion of the first conductor and the second conductor is housed in the insulating sleeve, the coil end of the stator can be shortened, and a compact stator can be provided.

  The invention described in (7) is the coil manufacturing method described in (6), wherein the first conductor and the second conductor are upset welded by applying pressure to the first conductor and the second conductor and passing an electric current. Therefore, the mechanical strength at the welded portion of the first conductor and the second conductor is easily obtained.

  Further, the invention described in (8) is the coil manufacturing method described in (6) or (7), wherein an insulating sleeve made of ceramic is inserted into a slot portion formed in the stator core, and inside the insulating sleeve, Since the first conductor and the second conductor are inserted and the end faces are joined to each other, the possibility that the insulation between the first conductor and the second conductor becomes defective due to heat during joining is reduced.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
In FIG. 1, the perspective view of the stator 10 of 1st Embodiment is shown.
A stator 10 shown in FIG. 1 is used for a motor mounted on a hybrid vehicle, and a first upper surface side insertion conductor 12 a and a first lower surface side insertion conductor 12 b are inserted into a stator core 11. Terminals 15 for each phase are attached to the upper surface of the first upper surface side insertion conductor 12a.
The stator core 11 is formed by laminating electromagnetic steel plates, and has a cylindrical shape, and grooves called slots 11a and protrusions called teeth 11b are alternately formed on the inner peripheral side.
The first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are obtained by overlapping a plurality of conductors.

FIG. 2 shows an exploded view of the first upper surface side insertion conductor 12a.
The first upper surface side insertion conductor 12a is composed of a plurality of plastically processed conductors. For convenience, the first U-shaped conductor 121 is arranged inside the stator core 11, then the second U-shaped conductor 122, the third U-shaped conductor 123, the fourth U-shaped conductor 124, and the fifth U-shaped conductor 124. U-shaped conductor 125, 6th U-shaped conductor 126, 7th U-shaped conductor 127, 8th U-shaped conductor 128, 9th U-shaped conductor 129, 10th U-shaped conductor 130, 11th U-shaped conductor A conductor 131 is used. In addition, in order to form each phase, the part which connects the terminal 15 is needed, Therefore In addition to the 1st U-shaped conductor 121 thru | or the 11th U-shaped conductor 131, the connecting wire conductor 120 which is not U-shaped. In addition, a connection conductor 132 is prepared.

The 1st U-shaped conductor 121 thru | or the 11th U-shaped conductor 131, the crossover conductor 120, and the connection conductor 132 are copper or aluminum conductors, and each is cold-forged.
The first U-shaped conductor 121 to the eleventh U-shaped conductor 131 include three insertion portions 12aa, a coil end portion 12ab, and a step portion 12ac that are inserted into the insulating sleeve 13 when assembled to the stator 10. Consists of places.
The crossover conductor 120 includes an insertion portion 12aa, a step portion 12ac, and a crossover portion. The connection conductor 132 includes an insertion portion 12aa, a step portion 12ac, and a connection portion.
Here, for example, when the insertion portion 12aa of the first U-shaped conductor 121 is inserted into the insulating sleeve 13, one insertion portion 12aa is inserted into the first through hole 13a of the insulating sleeve 13 and the other insertion is performed. The part 12aa is inserted into the second through hole 13a. That is, the coil end portion 12ab is connected across different through holes 13a.

Hereinafter, when simply referred to as the insertion portion 12aa or the stepped portion 12ac, for convenience, the first U-shaped conductor 121 to the eleventh U-shaped conductor 131 and all or any of the portions provided in the crossover conductor 120 and the connecting conductor 132 are used. Point to.
In addition, when simply referred to as the coil end portion 12ab, for convenience, it refers to all or any of the portions provided in the first U-shaped conductor 121 to the eleventh U-shaped conductor 131.

The insertion portion 12aa to be inserted into the insulating sleeve 13 is formed so that the one disposed inside the stator core 11 has a wide radial width of the stator core 11. The insertion portion 12aa is formed such that the radial width of the stator core 11 is gradually narrowed from the inner peripheral portion of the stator core 11 to the outer peripheral portion.
The insertion portion 12aa is formed so that the circumferential width of the stator core 11 is narrow. The insertion portion 12aa is formed so that the circumferential width of the stator core 11 gradually increases as it goes from the inner peripheral portion of the stator core 11 to the outer peripheral portion.
Note that the shape of the insertion portion 12aa inserted into the outermost peripheral portion of the stator core 11 is a semicircular shape that protrudes toward the outer peripheral side of the stator core 11.

In addition, the coil end portion 12ab is formed in a twisted shape so as not to interfere with the adjacent coil end portion 12ab. The coil end portion 12ab is coated with an insulating resin such as amide imide before being overlaid as the first upper surface side insertion conductor 12a.
The coating portion of the insulating resin is applied up to the step portion 12ac, and the insertion portion 12aa is not coated.
The connecting portion between the insertion portion 12aa and the coil end portion 12ab is provided with a step portion 12ac so that it can be positioned when the first upper surface side insertion conductor 12a is disposed on the stator core 11.
The first U-shaped conductor 121 to the eleventh U-shaped conductor 131, the crossover conductor 120, and the connecting conductor 132 are designed to have the same cross-sectional area.
A chamfer (chamfering) is formed on the upper end 12ad, which is the end of the insertion portion 12aa. The chamfer angle is preferably about 5 ° to 20 ° from the end face. In addition, the chamfer processing can be substituted by a shape in which two surfaces such as a cut surface cut by a clipper intersect at an acute angle.

As a part corresponding to the first upper surface side insertion conductor 12a, there is a first lower surface side insertion conductor 12b shown in FIGS. 5 and 6, or a second upper side insertion conductor 12c and a second lower side insertion conductor 12d (not shown).
Each of them is formed by stacking a plurality of conductors formed by cold forging in a U-shape and has a similar shape.
The first upper surface side insertion conductor 12a is joined to the first lower surface side insertion conductor 12b as shown in FIGS. 5 and 6 in order to form the shape of the coil 12. Therefore, the insertion portion 12ba corresponding to the insertion portion 12aa is provided, and the insertion portions 12ba are connected at portions corresponding to the coil end portions 12ab, respectively.
However, the difference from the first upper surface side insertion conductor 12a is that the first lower surface side insertion conductor 12b is connected to the first upper surface side insertion conductor 12a to form the shape of the coil 12, so that the innermost circumference of the stator core 11 is formed. This is a point where the insertion parts 12ba located in the part are connected to each other.

The first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are required to have another type. This is because it is necessary to prepare right-handed and left-handed coils. The external appearance is substantially the same as the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b shown in FIG. 6, but the correspondence relationship between the insertion portion 12aa connected to the coil end portion 12ab is reversed. An upper insertion conductor 12c and a second lower insertion conductor 12d are prepared.
Since the first lower surface side insertion conductor 12b and the second lower side insertion conductor 12d are similarly connected to the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b, it can be designed as a common component. is there.
In order to form the first upper surface side insertion conductor 12a, the first lower surface side insertion conductor 12b, the second upper side insertion conductor 12c, and the second lower side insertion conductor 12d, it is necessary to cold forge the number of conductors to be overlaid. A mold is required.

FIG. 3 shows a perspective view of the insulating sleeve 13.
The insulating sleeve 13 is formed using ceramics such as cordierite or alumina. Since they have the same cross-sectional shape, they may be formed using a technique such as extrusion.
The insulating sleeve 13 has a rectangular shape at eleven locations and a semicircular through hole 13a at one location. The through hole 13a has the same cross-sectional shape as the insertion portion 12aa, and the insertion portion 12aa is inserted therein.
Accordingly, the through-hole 13a that comes to the inner peripheral side of the stator core 11 when inserted into the stator core 11 is formed to be wide in the radial direction of the stator core 11 and narrow in the circumferential direction. Then, gradually reaching the outer peripheral side, the stator core 11 is formed narrow in the radial direction and wide in the circumferential direction. However, only the through-hole 13a located at the outermost periphery of the stator core 11 has a semicircular shape that protrudes toward the outer periphery, similarly to the cross section of the insertion portion 12aa disposed at the same position.

The through-hole 13a of the insulating sleeve 13 is formed by being partitioned by a partition wall 13b, and the partition wall 13b is inserted when the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are inserted and energized as the stator 10. It is set to a thickness that can be reliably insulated.
FIG. 4 is a perspective view showing a state in which the insulating sleeve 13 is inserted into the slot 11 a of the stator core 11.
The plurality of slots 11a formed in the stator core 11 are designed to have a size that allows the insulating sleeve 13 to be easily inserted.

Next, the configuration of the coil will be described.
FIG. 5 is a perspective view illustrating a state in which the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are connected. FIG. 6 is a perspective view illustrating a state in which the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are joined.
As shown in FIG. 2, the first upper surface side insertion conductor 12 a and the first lower surface side insertion conductor 12 b include the first U-shaped conductor 121 to the eleventh U-shaped conductor 131, the crossover conductor 120, and the connection conductor 132. It is a layered one.
In order to join the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b, the upper end portion 12ad which is the end portion of the first upper surface side insertion conductor 12a and the end portion of the first lower surface side insertion conductor 12b are used. A certain lower end 12bd is faced and faced.
Then, as shown in FIG. 6, the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are joined by applying pressure while applying pressure while the upper end portion 12ad and the lower end portion 12bd are in contact with each other.

This way of pressurizing the conductors and flowing a large current to join them is called upset welding. Upset welding is a type of resistance welding and is sometimes called slow butt welding or butt welding.
In the abutting surface 12f formed by abutting the upper end portion 12ad and the lower end portion 12bd, as shown in FIG. 6, the resistance value is highest when a current is passed through the upper end portion 12ad and the lower end portion 12bd. . Therefore, heat is generated by the contact resistance generated at the butting surface 12f and the specific resistance of the material, and the temperature near the butting surface 12f increases.
In the first embodiment, a voltage of about 5000 V is applied to the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b, and the butt formed by the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b. A load of about 5 kg is applied toward the surface 12f.
In this way, the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are upset welded and joined at the butting surface 12f to form one coil 12.

Note that two types of the coil 12 are required to form the stator 10. The coil 12 is formed by the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b, and the coil 12 is formed by the second upper side insertion conductor 12c and the second lower side insertion conductor 12d.
The coil 12 formed by the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b is right-handed, and the coil 12 formed by the second upper side insertion conductor 12c and the second lower side insertion conductor 12d is left-handed. It becomes. A circuit that functions as the stator 10 can be formed by combining these two types of coils.

Incidentally, the first upper surface side insertion conductor 12 a to the second lower side insertion conductor 12 d are not directly inserted into the stator core 11. An insulating sleeve 13 is inserted in the stator core 11 in advance, and the insertion portion 12aa and the like are inserted into the through hole 13a of the insulating sleeve 13.
FIG. 7 is a perspective view illustrating a state in which the first upper surface side insertion conductor 12 a and the first lower surface side insertion conductor 12 b are inserted into the insulating sleeve 13. FIG. 7 corresponds to FIG. FIG. 8 is a perspective view illustrating a state in which the first upper surface side insertion conductor 12 a and the first lower surface side insertion conductor 12 b are inserted into the insulating sleeve 13. FIG. 8 corresponds to FIG.
As shown in FIG. 7, the first upper surface side insertion conductor 12 a and the first lower surface side insertion conductor 12 b have the insertion portion 12 aa inserted into the insulation sleeve 13, and the upper end portion 12 ad and the lower end portion 12 bd inside the insulation sleeve 13. In the state where the abuts, the state shown in FIG. 8 is obtained.
The second upper insertion conductor 12c and the second lower insertion conductor 12d have substantially the same shape.

FIGS. 5 to 7 show the state in which the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are joined individually, but actually they are inserted into the stator core 11 and joined. This will be described with reference to FIGS.
FIG. 9 is a perspective view illustrating how the insulating sleeve 13 is inserted into the stator core 11. FIG. 10 is a perspective view illustrating how the upper surface side insertion unit 12A is inserted. FIG. 11 is a perspective view illustrating how the lower surface side insertion unit 12B is inserted. FIG. 12 is a perspective view of the stator 10 in a state where the upper surface side insertion unit 12A and the lower surface side insertion unit 12B have been inserted.
The insulating sleeve 13 is inserted into the slot 11a of the stator core 11 as described with reference to FIG. Since the stator core 11 has 48 slots 11a, as shown in FIG. 9, the insulating sleeve 13 is inserted into each of them.

Then, the upper surface side insertion unit 12 </ b> A is inserted into the through hole 13 a of the insulating sleeve 13 inserted into the stator core 11.
The upper surface side insertion unit 12A is a unit composed of 12 first upper surface side insertion conductors 12a and 12 second upper surface insertion conductors 12c, and the first upper surface side insertion conductor 12a and the second upper surface insertion conductor 12c. Are arranged alternately to form a circular shape.
If it is difficult to insert the upper surface side insertion unit 12A into the insulating sleeve 13 at a time, it is possible to prevent a process such as inserting the first upper surface side insertion conductor 12a as a unit.
In this way, the formed upper surface side insertion unit 12A is inserted into the insulating sleeve 13 provided in the stator core 11 as shown in FIG.

Also in the case of the lower surface side insertion unit 12B, it is inserted as shown in FIG. 11 in the same manner as the upper surface side insertion unit 12A.
The lower surface side insertion unit 12B is a unit composed of twelve first lower surface side insertion conductors 12b and twelve second lower surface insertion conductors 12d. The conductors 12d are alternately arranged to form a circular shape.
In FIG. 11, it is shown that it is inserted from the lower surface of the stator core 11, but for the convenience of the process, the upper surface side insertion unit 12 </ b> A is inserted because it is easier to obtain accuracy when inserted from the upper side. This prevents the stator core 11 from being turned over and inserting the lower surface side insertion unit 12B from the upper surface side.

The state where the upper surface side insertion unit 12A and the lower surface side insertion unit 12B are thus inserted into the stator core 11 is shown in FIG. In this state, upset welding is completed by pressurizing and energizing the upper surface side insertion unit 12A and the lower surface side insertion unit 12B.
Then, the electrical circuit of the stator 10 is formed by joining the U-phase terminal 15U, the W-phase terminal 15W, and the V-phase terminal 15V to the upper surface side insertion unit 12A side.
Thereafter, the coil end is resin-molded or varnished on the coil end to ensure insulation of the coil end.

Since 1st Embodiment shows the structure and effect | action demonstrated above, there exists an effect demonstrated below.
First, the first effect is that the coil end can be shortened.
In a stator 10 of a motor including a stator core 11 formed by stacking steel plates and a coil 12 disposed on the stator core 11, a first U-shaped conductor 121 formed in a substantially U-shape by plastic working. 1st upper surface side insertion conductor 12a and 2nd upper side insertion conductor 12c which form a part of coil 12, and a 1st lower surface side insertion which forms a part of coil 12 are piled up thru | or 11th U-shaped conductor 131. A conductor 12b and a second lower insertion conductor 12d are formed, and the end surfaces of the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are second in the slot 11a formed in the stator core 11. The end surfaces of the upper insertion conductor 12c and the second lower insertion conductor 12d are joined together to form a coil shape, which is disposed on the stator core 11.

In this way, the upper end 12ad and the lower end 12bd of the first upper surface side insertion conductor 12a to the second lower side insertion conductor 12d in which the coil end portion 12ab is plastically processed by a press device or the like are brought into contact with each other to be joined. Since the coil 12 of the stator 10 is formed, the coil end portion such as the coil end portion 12ab can be optimized, and the coil end can be shortened.
This is because it is not necessary to form the welded portion at the coil end as in the techniques disclosed in Patent Document 2 and Patent Document 3, and since the flat member is not formed by bending, the anti-lead which is not the welded portion. This is because it is not necessary to secure the minimum bending radius of the flat rectangular material at the coil end on the side.
That is, if the upper surface side insertion unit 12A and the lower surface side insertion unit 12B form a joint surface inside the stator core 11, there is no need to form a welded portion on the outside, and therefore the coil end can be shortened.

Further, as a second effect, by joining the upper surface side insertion unit 12A and the lower surface side insertion unit 12B by upset welding, it becomes possible to join the abutting surface 12f of the coil 12 while obtaining a certain degree of mechanical strength. .
The upper surface side insertion unit 12A and the lower surface side insertion unit 12B are upset welded by applying pressure and applying current to the upper surface side insertion unit 12A and the lower surface side insertion unit 12B.
Since the upper surface side insertion unit 12A and the lower surface side insertion unit 12B are joined by upset welding, mechanical strength can be obtained rather than simple brazing.

The third effect is that the insulating sleeve 13 is made of ceramic, so that the insulating portion is not deteriorated by heat even when a bonding method is selected so that the temperature becomes high at the time of bonding.
The ceramic insulating sleeve 13 is inserted into the slot 11a formed in the stator core 11, and the insertion portion 12aa of the upper surface side insertion unit 12A and the insertion portion 12ba of the lower surface side insertion unit 12B are inserted into the insulation sleeve 13. Therefore, it is possible to ensure insulation when performing upset welding, flash welding, or the like.
In joining upper surface side insertion unit 12A and lower surface side insertion unit 12B, methods, such as brazing and welding, are considered.

However, even if brazing is performed, a certain temperature is required, and in the case of welding, the temperature is considerably high. Therefore, it is difficult to maintain the insulating property with a resin material. In this regard, if the insulating sleeve 13 is formed using a ceramic material, at least the temperature problem can be solved.
As for the impact resistance, which is a concern when using ceramic materials, as long as the applicant confirmed, it was confirmed that even if welding such as upset welding was performed inside the insulating sleeve 13, it was not damaged.
When used as the stator 10, the thermal cycle becomes a problem, but it can be considered that the insulating sleeve 13 made of ceramic can withstand use from the result of the thermal cycle test.

Further, as another effect, it is possible to effectively arrange the coil 12 with respect to the stator core 11 by making one end of the insulating sleeve 13 into a semicircular shape.
The insertion portion 12aa located on the outer peripheral side of the stator core 11 of the first upper surface side insertion conductor 12a to the second lower side insertion conductor 12d has a semicircular shape. This is because the shape of the slot 11a formed in the stator core 11 is effectively used. The slot 11a formed in the stator core 11 has a round outer peripheral side. This is because merits such as not inhibiting the generation of eddy current are expected.
However, when a flat conducting wire or the like is used, a gap where no conductor enters is generated on the outer peripheral side of the slot 11a. Since this portion is a loss for the motor using the stator 10, the insertion portion 12aa located on the outer peripheral side of the stator core 11 of the first upper surface side insertion conductor 12a to the second lower side insertion conductor 12d is formed into a semicircular shape. Thus, the design can be made without any gaps.
As a result, the stator 10 can be reduced in size.

(Second Embodiment)
The second embodiment is substantially the same as the configuration of the stator 10 of the first embodiment, but the shapes of the upper end portion 12ad included in the upper surface side insertion unit 12A and the lower end portion 12bd included in the lower surface side insertion unit 12B are the same. Different. Only the differences will be described below.
FIG. 13 is a perspective view showing a state in which the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b of the second embodiment are joined.
The upper end portion 12ad of the first upper surface side insertion conductor 12a is arranged in a step shape so that the length of the insertion portion 12aa becomes longer toward the outer peripheral side of the stator core 11.
On the other hand, the lower end portion 12bd of the first lower surface side insertion conductor 12b is arranged in a stepped manner so that the length of the insertion portion 12ba becomes shorter as it goes to the outer peripheral portion of the stator core 11.
By forming in this way, the butting surface 12f formed when the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b are joined is formed in a step shape.

The length of the insertion portion 12aa of the first upper surface side insertion conductor 12a is shortened toward the outer peripheral side of the stator core 11, and the length of the insertion portion 12ba of the first lower surface side insertion conductor 12b is the outer peripheral side of the stator core 11. It may be formed to become longer as it goes.
Similarly, the second upper insertion conductor 12c and the second lower insertion conductor 12d are designed so that the abutting surface 12f is formed in a step shape.

Thus, the effects described below can be expected by forming the shapes of the upper end 12ad and the lower end 12bd of the upper surface side insertion unit 12A and the lower surface side insertion unit 12B.
There are various methods for joining the upper surface side insertion unit 12A and the lower surface side insertion unit 12B. However, when joining by welding such as upset welding, there is a problem that a poorly welded portion occurs.
This is because if air is entrained and joined to the butting surface 12f, the resistance value of that portion becomes high. When the resistance value of a part of the coil 12 is increased, heat is partially generated and the stator 10 is deteriorated.

Therefore, it is important not to produce this welding defect, and it is necessary to investigate whether or not the welding was successful.
When inspecting a welded portion, a method of confirming through transmission with X-rays or the like is conceivable. At this time, the position of the welding failure is easier to grasp if the butt surface 12f is stepped. This is because in the case of investigating with X-rays, the position of the defect appears as whitish because it is an air layer. If it becomes easy to specify the position of the bonding failure, it is possible to contribute to the investigation of the cause.

Although the invention has been described according to the present embodiment, the invention is not limited to the embodiment, and by appropriately changing a part of the configuration without departing from the spirit of the invention. It can also be implemented.
For example, the materials shown in the first embodiment and the second embodiment are not particularly limited, and alternatives can be used.
Further, the shape of the first upper surface side insertion conductor 12a to the second lower side insertion conductor 12d, the shape of the stator core 11, and the like are not limited to the illustrated shapes.
In addition, in the embodiment, upset welding is also used for the method of joining the first upper surface side insertion conductor 12a and the first lower surface side insertion conductor 12b and the method of joining the second upper side insertion conductor 12c and the second lower side insertion conductor 12d. However, it does not prevent the use of flash welding or brazing.

The perspective view of the stator 10 of 1st Embodiment is shown. The exploded view of the 1st upper surface side insertion conductor 12a of a 1st embodiment is shown. The perspective view of the insulation sleeve 13 of 1st Embodiment is shown. The perspective view showing a mode that the insulating sleeve 13 of 1st Embodiment is inserted in the slot 11a of the stator core 11 is shown. The perspective view explaining a mode that the 1st upper surface side insertion conductor 12a and the 1st lower surface side insertion conductor 12b of a 1st embodiment are connected is shown. The perspective view explaining a mode that the 1st upper surface side insertion conductor 12a and the 1st lower surface side insertion conductor 12b of 1st Embodiment were joined is shown. The perspective view explaining a mode that the 1st upper surface side insertion conductor 12a and the 1st lower surface side insertion conductor 12b were inserted in the insulation sleeve 13 of 1st Embodiment is shown. The perspective view explaining a mode that the 1st upper surface side insertion conductor 12a and the 1st lower surface side insertion conductor 12b were inserted in insulating sleeve 13 of a 1st embodiment is shown. The perspective view explaining a mode that insulating sleeve 13 is inserted in stator core 11 of a 1st embodiment is shown. The perspective view explaining a mode that the upper surface side insertion unit 12A of 1st Embodiment is inserted is shown. The perspective view explaining a mode that the lower surface side insertion unit 12B of 1st Embodiment is inserted is shown. The perspective view of the stator 10 of the state which finished inserting the upper surface side insertion unit 12A and the lower surface side insertion unit 12B of 1st Embodiment is shown. The perspective view of the state which joined the 1st upper surface side insertion conductor 12a and the 1st lower surface side insertion conductor 12b of 2nd Embodiment is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stator 11 Stator core 11a Slot 11b Teeth 12 Coil 12A Upper surface side insertion unit 12B Lower surface side insertion unit 12a First upper surface side insertion conductor 12aa Insertion part 12ab Coil end part 12ac Step part 12ad Upper end part 12b First lower surface side insertion conductor 12ba Insertion portion 12bd Lower end portion 12c Second upper insertion conductor 12d Second lower insertion conductor 12f Abutting surface 13 Insulating sleeve 13a Through hole 13b Partition 15 Terminal 12aa Insertion portion 12ba Insertion portion

Claims (8)

In a stator of a motor comprising a stator core formed by stacking steel plates, and a coil disposed on the stator core,
A plurality of conductors formed in a substantially U shape by plastic processing are stacked, and a first conductor that forms a part of the coil and a second conductor that forms a part of the coil are formed,
A stator of a motor, wherein the end surfaces of the first conductor and the second conductor are joined to each other inside a slot portion formed in the stator core to form a coil shape and are arranged in the stator core. In the stator of the motor according to claim 1,
An insulating sleeve made of ceramic is inserted into the slot portion formed in the stator core,
A stator for a motor, wherein the first conductor and the second conductor are inserted into the insulating sleeve, and end faces are joined to each other. In the stator of the motor according to claim 1 or 2,
A stator for a motor, wherein the first conductor and the second conductor are pressurized and the current is passed to upset the first conductor and the second conductor. In the stator of the motor according to claim 2 or claim 3,
The end portion of the insulating sleeve that becomes the outer peripheral side when inserted into the stator core is formed in a semicircular shape, and the first conductor and the second conductor inserted into the insulating sleeve also correspond to a semicircular shape. The stator of the motor characterized by being formed in. In the stator of the motor according to any one of claims 1 to 4,
A stator for a motor, wherein an end face of the first conductor and an end face of the second conductor are formed in a stepped shape. In a coil manufacturing method for forming a coil shape by inserting a conductor forming a part of a coil into a stator core formed by laminating steel plates, and joining the conductors,
The conductor is formed in a substantially U shape by plastic working,
A first conductor that overlaps a plurality of the conductors and is inserted from one surface of the stator core;
A plurality of the conductors are overlapped, and a second conductor inserted from the other surface of the stator core is formed,
To the slot formed in the stator core,
Inserting the first conductor from one side of the stator core;
Inserting the second conductor from the other surface side of the stator core;
A coil manufacturing method comprising forming the coil shape by bringing an end face of the first conductor inserted into the stator core into contact with an end face of the second conductor and joining them. In the coil manufacturing method according to claim 6,
A coil manufacturing method, wherein the first conductor and the second conductor are upset welded by applying pressure to the first conductor and the second conductor and passing an electric current. In the coil manufacturing method according to claim 6 or 7,
An insulating sleeve made of ceramic is inserted into the slot portion formed in the stator core,
The coil manufacturing method, wherein the first conductor and the second conductor are inserted into the insulating sleeve, and end faces are joined to each other.

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