JPH0681453B2 - Coil forming equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a coil mounted on a stator of a rotary electric machine, and more particularly to a coil forming apparatus suitable for a coil forming operation in one step.

[Background of the Invention]

In the conventional coil molding, molding of both coil end portions consisting of a coil end portion projecting at one end in the axial direction of the stator and a coil end portion projecting at the other end and molding of the coil in the slot are carried out separately, In such cases,
It is difficult for previously formed coils to maintain a given size. Moreover, this tendency is remarkable when the coil ends are not bound by the thread or the like.

As a supplement to this shortcoming, there is Jitsuko Sho 51-36162. This is to make it easier to insert the auxiliary coil by expanding the main coil previously inserted into the slot in the slot into which the main coil and the auxiliary coil are inserted. When there is a main coil and an auxiliary coil in this way, the space factor in the slot of the coil inserted earlier is extremely low.If only both coil ends are molded, the coil in the slot will be the inner diameter of the stator. If only the coil in the slot is molded, both coil ends will fall in the inner diameter direction. Therefore, it is necessary to form both coil ends and the coil in the slot at the same time. In this known example, there is a corresponding pair of rams and associated coil end forming pieces, and an expansion blade for forming a coil in a slot, and the expansion blade moves forward and backward together with one ram. The coil forming portion in the slot of the expansion blade has a T-shaped cross section wider than the other portions, so that a wide range in the slot can be pushed. Therefore, the expansion blade T-shaped portion is inserted into the slot from the end face of the core. In the semi-closed slot, the slot opening is narrow and the inside of the slot is wide. Since this tendency becomes remarkable especially when the number of slots is small, this known example is very significant. Further, both coil end portions can be adjusted in molding amount separately from the expansion blade by changing the inclination of unevenness. Therefore, this known example is useful for so-called intermediate molding.

When the coil is inserted, a horn having a conical tip is normally inserted from the coil insertion side, the coil on the opposite side is opened to some extent to the outer diameter, and then the coil end is formed. However, since this involves two steps, it is the fact that this is combined into one step, such as Jitsuko 54-131002.
This is a device in which the horn is inserted from the insertion side, the coil on the opposite side is expanded, and then the coil end is molded.

By the way, the technological innovation in the stator electric work in recent years is remarkable, and not only the high space factor in the slot but also the space factor in the aile end part is getting higher. Moreover, in such a case, it is advantageous to insert in one step.

FIG. 1 shows the appearance of the stator inserted in one step. The stator 1 shown in FIG. 1 is a coil 2 using an insert method.
It shows the state that it is attached by inserting
At the time of insertion, the coil 2 is inserted into the stator 1 from the upper end side to the lower end side in the axial direction while being pressed, so that the coil is inserted on the upper end side and the lower end side of the stator 1 which are opposite to the insertion side. The end portions respectively project, and the coils are also inserted into the slots of the stator 1. In this case, the coil end portions are open to each other on the insertion side of the stator 1, but the coil end portions are tilted toward the inner diameter side of the stator 1 on the non-insertion side. In order to complete the finish forming in one step, it is necessary to first pass through a horn with a conical tip and then immediately form, but at this time, the space factor in the slot is high and the coil end length is Both short coil ends must be molded without damaging them, and the coil in the slot must also be molded. Moreover, in order to mold the stator having the windings inserted in all the slots, coil forming blades in the slot corresponding to all the slots are required, and this must move radially. Further, it is not preferable that the forming blade in the slot advances or retreats in the axial direction of the slot while touching the coil or the insulator because it may damage the coil or move the insulator. Furthermore, having a groove in which the in-slot molding blade and the coil-end molding piece fit together means that when a stator with no significant difference between the coil-end molding size and the in-slot coil molding size is formed, the coil fits in the mating groove. It is easy to think of scratching. Therefore, it is better that the forming piece and the horn with a conical tip do not have grooves for advancing and retracting other forming pieces for forming the coil, but in conventional forming machines, slot forming blades, etc. Many have a fitting groove.

[Object of the Invention]

An object of the present invention is to solve the above-mentioned problems and to provide a coil forming apparatus for performing a coil forming operation in one step.

According to the present invention, when the stator having the coil attached thereto is conveyed to the coil forming position along the vertical direction on the insertion side at one end in the axial direction and the non-insertion side at the other end, the stator is inserted in the coil. The upper coil end portion projecting to the side, the lower coil end portion projecting to the side opposite to the stator insertion side, and the slot coil portion arranged in the slot of the stator are each formed in a desired shape.

That is, the present invention includes a transfer chuck that transfers the stator to a coil forming position, upper and lower plates that are arranged at positions facing each other with the positioned stator interposed therebetween, and that are vertically movably supported. A lower contour forming piece that is disposed on the lower plate and that can move toward the outer periphery of the lower coil end portion of the stator; and a lower coil that is movably attached to the lower coil portion of the stator on the lower plate. In the upper plate, a lower height forming piece that regulates the height position of the end portion, an operating plate that is attached to the upper surface plate, and has an upper outer shape forming piece that can move toward the outer periphery of the upper coil end portion of the stator. An upper height forming piece that is movably attached toward the tip of the upper coil portion of the stator and that regulates the height position of the upper coil portion, and a stator at the bottom of the top plate. Inner diameter moldings mounted concentrically with the stator at opposed positions, the upper plate, the lower plate, the lower outer shape molding piece, the lower height molding piece, the working plate, the upper height molding piece, and the upper outer shape molding piece, respectively. And a drive source for driving.

The inner diameter molded body is coaxially connected to a holding rod connected to the bottom portion of the upper surface plate and a tip of the holding rod at a desired interval so as to pass through the inside of the stator and remove the lower coil end portion of the stator. An inner diameter expanding portion that can be expanded in one direction, a forming blade that is movably mounted between the inner diameter expanding portion and the holding rod in the radial direction, and is composed of a plurality of blades corresponding to the respective numbers of slots of the stator. A biasing member that biases the forming blade in the centripetal direction between the inner diameter expansion portion and the holding rod, a cone that moves each forming blade in the radial direction against the biasing member, and a drive unit for the cone. ing.

Each of the forming blades is formed on the upper and lower portions of the outer end surface thereof, and the outer circumferences of the upper coil end portion and the lower coil end of the stator can be pressed against the upper and lower outer shape forming pieces. And formed with an outer diameter smaller than the upper and lower inner diameter molding portions between the upper and lower inner diameter molding portions, respectively.
And a slot coil molding portion that can be inserted into each slot of the stator and can press the slot coil portion toward the outer peripheral side of the stator.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 2 to 8.

The stator 1 having the coil 2 as shown in FIG. 1 is carried to the coil forming position by the carrying chuck 17 of the apparatus as shown in FIG. In this case, the transport chuck 17
Is a configuration in which the coil end portion on the insertion side of the stator 1 (hereinafter, simply referred to as the upper coil end portion) is on the upper side, and the coil end portion on the non-insertion side (hereinafter, simply, the lower coil end portion) is at the lower side. Then, the stator 1 itself is gripped and conveyed to the coil forming position.

In FIG. 2, reference numeral 33 is a bottom plate, on which the lower height forming piece driving portion 19, the driving portion holding portions 36 and 36 ', and the lower height forming piece are formed.
A guide 40 for guiding the forward / backward movement of 18, a lower outer shape forming piece driving unit 32 and a lower outer shape forming piece 8 are attached. The lower surface plate 33 is driven by a drive source (not shown).
Ascended by being guided by 35. The lower height forming driving unit 19 is fixed to the lower surface plate 33 via the drive holding units 36 and 36 ', and the rod thereof raises the lower height forming piece 18. The lower height molding piece 18 regulates the lower end of the lower coil end portion of the stator 1, and has a cylindrical shape along the lower coil end portion. The lower outer shape forming piece 8 is a lower outer shape forming piece drive unit 32.
Drive to move forward and hit the outer circumference of the lower coil end portion of the stator 1 to regulate the outer circumference of the lower coil end portion. Therefore, the lower outer shape forming piece 8 has a tubular shape along the outer periphery of the lower coil end portion, and in the present example,
As shown in the figure, each is divided into three parts on the circumference and independently driven by the respective lower outer shape molding piece driving parts 32.

In this case, the lower outer diameter forming piece 8 is divided into three parts because the coils are separately installed in the stator 1 into three sets of inner coils and three sets of outer coils.

On the other hand, the upper surface plate 25, which is installed so as to face the lower surface plate 33, is moved down by being guided by the drive rod 37 by a drive source (not shown). The upper plate 25 has an upper-height forming piece driving unit for driving an upper-height forming piece 18 ', which will be described later.
28 is attached via connecting bodies 29, 29 ', and the operating plate 9 is attached to the bottom portion thereof via a spacer 30.

An upper outer shape molding piece drive unit 32 and an upper outer shape molding piece 8'are attached to the operating plate 9. As shown in FIG. 2, the upper height forming piece 18 'is connected to the rod of the upper height forming piece drive unit 28 by a connecting rod 27.
, And when descending by the drive unit 28,
It regulates the upper end of the upper coil end portion of the stator 1, and is formed in a cylindrical shape like the lower height forming piece 18, and is guided by a holding rod 24 of an inner diameter forming body described later. The upper outer shape forming piece 8 ′ is moved forward by the driving of the upper outer shape forming piece drive portion 32 and hits the outer circumference of the upper coil end portion of the stator 1 to regulate the outer circumference of the upper coil end portion. Therefore, the upper outer shape forming piece 8 ′ is divided into three parts along the outer circumference of the upper coil end portion like the lower outer shape forming piece 8.

Further, an inner diameter molding (not shown) is attached to the upper surface plate 25. As shown in FIGS. 2 and 3, the inner diameter molded body is connected to a holding rod 24 fixed to an upper surface plate 25, a lower portion of the holding rod 24 via a connecting rod 22, and a tip end thereof is conical. And an inner diameter expansion portion 20 having a shape. When the inner diameter expansion portion 20 descends as the top plate 25 descends, the inner diameter expansion portion 20 enters into the stator 1, passes between the upper coil end portion and the slot of the stator, hits the lower coil end portion of the stator 1, and By inserting the lower coil end portion as shown in the figure, the lower coil end portion is expanded. Therefore, the inner diameter expansion portion 20 is sized so that it can be inserted inward between the slots of the stator 1, and has the above-described conical shape so as to expand with the lower coil end portion. In addition, one end of the holding rod 24 is a holding rod.
It is connected to the lower part of 24 by a pin 23, and the other end is connected to the inner diameter expansion portion 20 by a pin 21.

Further, as shown in FIG. 3, grooves 20a, 24a, which are the same in number as the slots (not shown) of the stator 1, are radially formed on the surfaces of the inner diameter expansion portion 20 and the holding rod 24 which face each other.
A plurality of forming blades 16 are mounted between the grooves 20a and 24a so as to be movable in the radial direction. As shown in FIG. 3, the forming blade 16 has a lower inner diameter forming portion 16a at the lower portion of its outer end surface.
However, the upper inner diameter molding portion 16c is formed in the upper part, and the slot coil molding portion 16b is further formed between the upper inner diameter molding portion 16c and the lower inner diameter molding portion 16a. Normally, the inner diameter expansion portion 20 and the holding rod 24 are formed. Between them, they are located on the centripetal side so as to be in close contact with each other as shown in FIG. 4, and are moved in the radial direction as shown in FIG. 6 during coil forming.

As shown in FIG. 5, the slot coil molding portion 16b has a width 1 narrower than that of the lower inner diameter molding portion 16a and the upper inner diameter molding portion 16a, and has an outer shape smaller than both 16a and 16c. This width 1 is slightly narrower than the opening of the slot in the stator 1 so that it can enter the slot from the inner diameter side of the stator 1. In addition, the upper and lower inner diameter forming parts 16c and 16a are determined according to the dimensions required to form the inner diameters of the upper and lower coil end parts. Normally, the lower coil end part is considered in consideration of the coil backlash. The lower inner diameter forming portion 16a for forming is smaller in diameter than the upper inner diameter forming portion 16c. However, in the state before forming, as described above, the inner diameter forming portions 16a, 16c of both the upper and lower sides are located on the centripetal side so that the inner diameter does not become larger than the inner diameter of the stator 1 and the outer diameter is larger than the inner diameter expanding portion 20. It never happens. Therefore, each of the forming blades 16 is biased in the centripetal direction by the spring 38 as shown in FIG.

Further, inside the forming blade 16, a cone 39 for moving the forming blades 16 is provided. The cone
39 has a tubular shape as shown in FIGS. 2 and 3,
The upper end is connected to the cone drive unit 26 fixed to the upper surface plate 25, the tip side is inserted between the connecting rod 22 and the holding rod 24, and the tip portion is formed between the holding rod 24 and the inner diameter expansion section 20. It is located inside the blade 16. Further, on the outer periphery of the tip end portion of the cone 39, a sloped surface 39a having a shape substantially corresponding to the corrugated sloped surface provided inside each molding blade 16 is provided. And the cone 39
The upper outer shape molding piece 8'regulates the outer circumference of the upper coil end portion of the stator 1, the lower outer shape molding piece 8 regulates the outer circumference of the lower coil end portion, and the inner diameter molding body is inserted into the stator 1. When in the state, the cone drive section 26 advances, and when the slope 39a goes over the slope of each forming blade 16, each forming blade 16 is subjected to the spring force of the spring 39 between the holding rod 24 and the inner diameter expansion portion 20. However, as shown in FIG. 6, it is moved in the radial direction. Therefore,
When the forming blade 16 is moved in the radial direction, the upper inner diameter forming portion 16c and the lower inner diameter forming portion 16a of the forming blade 16 are moved to the stator 1.
The upper and lower coil end portions of the above are pressed against the upper outer shape forming piece 8'and the lower outer shape forming piece 8, and the slot coil forming portion 16b is inserted into the slot of the stator 1 to press the slot coil portion within the slot. I have to.

Since the coil forming apparatus of the embodiment has the above-mentioned configuration, its operation will be described next.

The stator 1 having the coil 2 mounted thereon has the coil end portion on the insertion side of the stator 1 facing upward and the coil end portion on the side opposite to the insertion side of the stator 1 facing downward.
When the sheet is conveyed by 17 and is conveyed to a predetermined position between the inner diameter molded body attached to the upper surface plate 25 and the lower surface plate 33, first, the lower surface plate 33 is raised by a drive source (not shown), and then the lower outer shape molding is performed. The lower outer shape forming piece 8 is moved forward by the driving of the drive portion 32, and the tip end surface of the lower outer shape forming piece 8 projects to the lower part of the stator 1, the outer peripheral surface of the lower coil end portion, the lower end surface of the stator 1, and the lower height. It abuts the molding piece 18 and stops.

After that, the upper surface plate 25 descends, and with this descending, the inner diameter molding and the upper outer shape molding piece 8 ′ also descend. At the time of the lowering, the inner diameter expanded portion 20 on the tip side of the inner diameter molded body moves toward the stator 1, reaches the lower coil end portion through the upper coil end portions and the slot coil portions of the stator, and further lowers. By pressing the lower coil end portion in the radial direction and expanding the lower coil end portion, the lower coil end portion is inserted and the state shown in FIG. 2 is obtained. At this time, the inner diameter expansion portion 20
Presses the lower coil end portion against the lower outer shape forming piece 8, so that the lower coil end portion is opened from the inner diameter side to the outer diameter side.

When the inner diameter expanded portion 20 is lowered, the upper coil end portion on the insertion side of the stator is expanded so that the inner diameter expanded portion 20 can be inserted as shown in FIG. 1 when the coil is inserted into the stator 1. Therefore, it does not interfere with anything other than the lower coil end portion.

Then, when the upper surface plate 25 stops, the upper outer shape forming piece 8'on the operating plate 9 is advanced by the upper outer shape forming drive unit 32, and the tip end surface of the upper outer shape forming piece 8'projects above the stator 1. The outer periphery of the end portion, the upper end surface of the stator 1 and the upper height forming piece 18 'are brought into contact with each other and stopped.

After that, when the cone 39 is lowered by the drive of the cone drive unit 26, each of the forming blades 16 is moved by the movement of the cone 39, and the urging force of the spring 38 is exerted between the holding rod 24 of the inner diameter molded body and the inner diameter expansion unit 20. While moving in the radial direction, the lower inner diameter forming portion 16a of the forming blade 16 firmly presses the inner peripheral side of the lower coil end portion of the stator 1 against the lower outer forming piece 8, and the upper inner diameter forming portion of the forming blade 16 is formed. The portion 16c firmly presses the inner peripheral side of the upper coil end portion of the stator 1 against the upper outer shape forming piece '. Further, the slot coil forming portion 16b of the forming blade 16 also moves at the same time to enter the slot in the stator 1 and press the slot coil portion against the stator 1.

In this state, the lower height forming piece driving part 19 is driven to raise the lower height forming piece 18, and the tip of the lower coil end portion presses the tip of the lower coil end portion to regulate it, while the upper height forming piece drive portion 28
The upper height molding piece 18 'is lowered by the driving of, and the tip of the upper coil end portion is pressed and regulated by the tip thereof.

Therefore, the upper coil end portion of the stator 1 is formed by the upper outer shape forming piece 8 ', the upper inner diameter forming portion 16c of the forming blade 16 and the upper height forming piece 18', and the lower coil end portion of the lower outer shape forming piece 8 is formed. The lower inner diameter forming portion 16a of the blade 16 is formed by the lower height forming piece 18, and since the slot coil portion is formed by the slot coil forming portion 16b of the forming blade 16, both the coil end portion and the slot coil portion are respectively formed. Can be simultaneously molded into a substantially desired shape. Moreover, after the inner diameter expanded portion 20 is first opened by inserting the lower coil end portion, the forming blade 16 is moved in the radial direction, and the three members of the upper / lower coil end portion and the slot coil end portion are moved to the inner diameter side. Since the molding blade 16 does not come into sliding contact with the coil wire and the coil wire is not damaged, the molding wire 16 does not touch the coil wire.

After forming in this way, after the upper height forming piece 18 'and the lower height forming piece 18 are retracted and the forming blade 16 is retracted,
By repeating the operation of the forming blade 16, cone 39, and upper and lower height forming pieces 18 '・ 18 several times, both coil end parts can be formed into a more reliable shape and the coil backlash is significantly reduced. Can be made.

After the coil of the stator 1 is formed in this way, the coil forming operation is completed by operating in the opposite manner and retracting, but after the upper outer shape forming piece 8 and the lower outer shape forming piece 8 are retracted, The upper surface plate 25 and the lower surface plate 33 may be retracted. In addition, when the stator 1 finishes forming the coil, the transfer chuck 17
Will be carried out, and the next stator 1 will be newly carried in.

Further, the inner diameter forming portion 16a of the forming blade 16 is the inner diameter expanding portion 2
When 0 descends inside the stator 1, the lower coil end portion of the stator 1 touches the lower coil end portion. However, since the portion that comes into contact with the coil is chamfered to a large extent, the inner diameter expansion portion 20 greatly expands the lower coil end portion. Therefore, there is no risk of damaging the coil, and since the coil is pressed in the direction in which it is inserted into the slot of the stator 1, there is no risk of causing a locking phenomenon between the coil and the inner diameter molding portion.

Further, as shown in FIG. 7, the upper and lower outer shape forming pieces 8 ′, 8 are formed with a projection 8 ″ projecting 2-3 mm at the center thereof, and the projection is mounted in the stator 1. The height is set to be slightly lower than the bending height of the insulator slot liner. The protrusion 8 ″ is located substantially at the center of the outer coil in each of the upper and lower coil end portions in the stator 1. During molding, when the upper and lower outer shape forming pieces 8 and 8'move forward and hit the upper and lower coil end portions, the stator 1 is positioned while preventing the upper and lower coil end portions from hanging downward. it can. This effect is great, the subsequent coil raising work can be omitted, and the labor can be saved.

Still further, the coil forming apparatus of the embodiment is, as described above,
Since each mechanism part is compounded so that the upper and lower coil end parts and the slot coil part can be molded in one process,
The equipment can be downsized. As a result, space can be saved, and the equipment cost can be reduced by about 40 to 50% as compared with the case where the coil end portions and the coil in the slot are molded separately. In addition, the coil forming work can be automated at low cost, and unmanned operation can be achieved.

[Advantages of the Invention] As described above, according to the present invention, when the stator having the coil inserted therein is conveyed, the inner diameter expanded portion of the inner diameter molded body is inserted into the stator from the upper coil end portion, and the lower coil is inserted. By inserting the end part while expanding it and moving the forming blade in the radial direction by the cone, the upper and lower inner diameter forming parts of the forming blade and the upper and lower outer shape forming pieces and
Since the upper and lower coil end portions are molded with the lower height molding piece, and the slot coil molding portion of the molding blade is configured to press the slot coil portion of the stator to mold the slot coil portion, There is an effect that the lower coil end portion and the slot coil portion can be surely molded in one step. In particular, since the backlash of the coil can be reliably reduced by repeatedly moving the inner diameter molded body with respect to the stator coil and moving the molding blade in the radial direction, the reliability of the molding apparatus can be improved. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a stator having a coil attached by an insert method, FIG. 2 is a partially cutaway sectional view showing an embodiment of a coil forming apparatus according to the present invention, and FIG. FIG. 4 is a plan view showing a position before the forming blade is moved, FIG. 5 is a plan view showing a slot coil forming part before the forming blade is moved, and FIG. FIG. 7 is a plan view showing a state when the forming blade is moved, FIG. 7 is an explanatory plan view when the upper and lower outer shape forming pieces are located at outer peripheral positions of the upper and lower coil end portions, and FIG. It is a perspective view which shows a part of the state which was done. 1 ... stator, 2 ... coil, 8 ... lower external molding piece,
8 '... upper outer molding piece, 8 "... projection, 9 ... operating plate,
10: Fixed plate, 16: Forming blade, 16a: Lower inner diameter forming part, 16b: Slot coil forming part, 16c: Upper inner diameter forming part, 17 ... Conveyor chuck, 18 ... Lower height forming piece , 18 '
...... Upper height molding piece, 19 ...... Lower height molding drive section, 20 ...... Inner diameter expansion section, 20a ...... Groove, 21 ...... Pin, 22 ...... Connecting rod, 23 ...... Pin, 24 ...... Holding Rod, 24a ... Groove, 25 ...
… Top plate, 26 …… Cone drive, 27 …… Connecting rod, 28 ……
Upper height molding piece drive part, 29, 29 '…… Coupling body, 30 …… Spacer, 32 …… Lower outer shape molding piece drive part, 33 …… Bottom plate, 35…
… Drive rods, 36,36 ′ …… Drive unit holders, 38 …… Springs, 39
……corn.

Claims (1)

[Claims] 1. When a stator having a coil mounted thereon is conveyed to a coil forming position along the vertical direction on the insertion side at one end in the axial direction and the non-insertion side at the other end, the stator of the coil A coil forming device for forming an upper coil end portion projecting to an insertion side, a lower coil end portion projecting to an opposite insertion side of a stator, and a slot coil portion arranged in a slot of a stator into desired shapes, respectively. A transfer chuck for transferring the stator to the coil forming position, and an upper and lower plate and a lower plate which are arranged at positions facing each other with the positioned stator interposed therebetween and which are movably supported in the vertical direction. And a lower outer shape forming piece that can move toward the outer periphery of the lower coil end portion of the stator and a lower plate that can move toward the tip of the lower coil portion of the stator. A lower height forming piece that is mounted on the upper surface plate and is movable toward the outer periphery of the upper coil end portion of the stator. The working plate, an upper height forming piece movably attached to the top plate toward the tip of the upper coil part of the stator, and regulating the height position of the upper coil part, and the stator at the bottom part of the top plate facing the stator. The inner diameter molded body mounted concentrically with the stator at the position, the upper surface plate, the lower surface plate, the lower outer shape molding piece, the lower height molding piece, the operating plate, the upper height molding piece, and the upper outer shape molding piece. The inner diameter molded body is coaxially connected to a holding rod connected to a bottom portion of the upper plate with a tip of the holding rod at a desired interval, and is inserted through the stator and the stator. Lower coil of A forming blade having an inner diameter expanding portion capable of expanding the end portion outward, and a plurality of blades mounted movably in the radial direction between the inner diameter expanding portion and the holding rod and corresponding to each slot number of the stator. A biasing member that biases each of the forming blades in the centripetal direction between the inner diameter expansion portion and the holding rod, a cone that moves each forming blade in the radial direction against the biasing member, and a drive unit for the cone. Each of the forming blades is formed on the upper and lower portions of the outer end surface thereof, and the outer peripheries of the upper coil end portion and the lower coil end portion of the stator can be pressed against the upper and lower outer shape forming pieces. An outer diameter smaller than the upper and lower inner diameter molding portions is formed between the lower inner diameter molding portion and each of the outer wall surface upper and lower inner diameter molding portions, and is inserted into each slot of the stator and the slot coil is provided on the outer peripheral side of the stator. Pressed on And a slot coil forming part that can be used.