JPH042104A - Method and device for peeling insulation film of flat type enamel wire - Google Patents

Abstract

PURPOSE:To eliminate the generation of peeling refuse, and to fix a coil such as a tap-less coil stably to a printed board by bringing a grindstone into contact with the surface of flat type enamel wire stretched to a block by adequate tension and peeling the insulating film of the flat type enamel wire by the rotary motion of the grindstone. CONSTITUTION:A grindstone 1 is brought into contact with the surface of a flat type enamel wire 31 stretched between moving and standing blocks 3a, 3b by proper tension so that the flat type enamel wire 31 is deflected slightly, and the insulating film of the flat type enamel wire 31 is peeled by the rotary motion of the grindstone 1 and reciprocating motion in the axial direction of the grindstone as required. Accord-to the method, melting refuse and combustion refuse do not adhere, thus mounting and fixing a coil such a tap-less coil to a printed board under a stable state without being disturbed by these melting refuse and combustion refuse.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a stator coil of a motor and a coil such as a rotary transformer, for example, as an electrode of a rectangular enameled wire constituting a tapless coil, which is connected to other conductive parts. Therefore, the present invention relates to a method and apparatus suitable for peeling off the insulating coating on the surface of the rectangular enameled wire.

[Summary of the Invention] The present invention is characterized in that a rotating grindstone is brought into contact with the surface of a rectangular enameled wire stretched on a pulley, and the insulating coating of the rectangular enameled wire is peeled off by the rotational movement of the rotating grindstone. The present invention provides an insulating coating peeling method and apparatus particularly suitable for forming electrodes of coils such as tapless coils using rectangular enameled wire.

[Conventional technology]

Generally, as shown in FIG. 6, in an enameled wire board with a circular cross section, the outer periphery of the conductive wire 52 is coated with an insulating coating 53 made of, for example, polyurethane resin or polyester resin. A fusion coating 54 made of vinyl butyral resin is coated. Hereinafter, the insulating coating 53 may include only the insulating coating 53 or the insulating coating 53 may be coated with a fusion coating 54.

As shown in FIG. 7, an enamelled wire plate made of the conducting wire 52 having such an insulating coating 53 is wound in alignment, and the coils 55 are fused and brought into close contact with each other.

A portion of the insulating coating 53 at the beginning and end of winding of this coil 55 is set to an appropriate length I! , 3 and 24 to form electrodes 55a and 55b at the beginning and end of winding, forming a coil 55 called a so-called tapless coil.

Regarding such a tapless coil 55, the applicant of the present invention previously filed an application as Japanese Patent Application Laid-open No. 56-49641. As a result, the conventional lead wire is omitted and the eighth
As shown in the figure, the tapless coil 55 is electrically and mechanically printed by soldering the electrodes 55a and 55b at the start and end of the winding of the tapless coil 55 to the circuit patterns 57 and 58 of the printed circuit board 56. It has become possible to mount and fix it on the board 56.

In addition, generally, as shown in FIG. 9, a normal coil 6
In order to connect the lead wire 61a of No. 1 with another conductive part to obtain continuity, an insulating coating 53 of the lead wire 61a of this coil 61 (the insulating coating 53 of No. 2 of the enameled wire is shown in FIG. 6) is used.
A solder dip method has been proposed in which both stripping and applying solder coating are performed. In this solder dip method, as shown in the drawing, a coil 6 is placed in molten solder in a solder bath 62.
The lead wire 61a of No. 1 was immersed, the insulating coating 53 of the lead wire 61a was melted and peeled off, and solder coating was performed.

In this solder dip method, the coil 61 having the lead wire 61a is coated with an insulating coating 53 at the tip of the lead wire 61a.
The tapless coil 55 according to the present invention has electrodes 55a at the beginning and end of the winding in the middle thereof.
, 55b, and in addition, the molten residue of the peeled insulating film 53 adheres to the boundary between the solder coated part and the unpeeled part of the insulating film 53, resulting in a tapless coil. 55 on the printed circuit board 56 and that it gets in the way when fixing it.

Conventionally, to form the tapless coil 55, before and after winding, the insulating coating 53 at the beginning and end of the winding of the enameled wire H of the tapless coil 55 is coated to an appropriate length! Only 3 and 14 were peeled off to form electrodes 55a and 55b at the beginning and end of winding. A conventional insulating coating 5 for forming these electrodes 55a and 55b is then used.
As the peeling method No. 3, a mechanical peeling method as shown in FIGS. 10 and 11 and an insulating coating peeling method using heat of laser light are known.

In the conventional mechanical insulation coating stripping method, as shown in FIG. The insulation coating 53 was peeled off.

This method of mechanically peeling off the insulation coating 53 requires rotating the cutter 63, and is not suitable for peeling off the insulation coating of a rectangular enameled wire that is not circular. Besides, cutter 63
The problem was that not only the mechanism was complicated, but also the adjustment was complicated. Moreover, the lifespan of the cutter 63 is also limited. Furthermore, in the case of a thin enamelled wire with a wire diameter of 0.1 wn or less, it is extremely difficult to peel off only the insulating coating 53 without damaging the conducting wire 52, which may cause wire breakage.

As shown in FIG. 11, the conventional method of peeling off the insulating coating 53 using the heat of laser light is as follows:
A laser beam 65 was irradiated by a laser device 64, and the insulating coating 53 of the enamel wire was burnt and peeled off by the energy.

However, in this method of peeling off the insulating coating 53 of the enameled wire using the heat of the laser beam, it is extremely difficult to burn only the insulating coating 53 without burning the conducting wire 52. Moreover, there was a problem in that it was extremely difficult to control the laser beam. Moreover, the burnt residue of the peeled insulation coating 53 adheres to the boundary between the conductor 52 portion from which the insulation coating 53 has been peeled off and the unpeeled portion of the insulation coating 53, and the tapless coil 55 is mounted on the printed circuit board 56. However, it has the disadvantage that it gets in the way when fixing it.

[Problem to be solved by the invention]

The present invention has been made to solve the above-mentioned conventional problems and drawbacks, and is particularly suitable for forming electrodes of coils such as tapless coils made of rectangular enamelled wire. To provide a method and device for stripping an insulating coating of a rectangular enamelled wire, which allows a coil such as a tapless coil to be stably fixed when mounted and fixed on a printed circuit board, for example, since molten scum and combustion scum do not adhere to the coil. is the issue.

[Means to solve the problem]

The present invention relates to a method and an apparatus for stripping the insulation coating of rectangular enamelled wire constituting a coil such as a tapless coil. A rotary grindstone is brought into contact with the surface of the stretched rectangular enameled wire so that the rectangular enameled wire is slightly bent, and the rotational motion of the rotary whetstone and, if necessary, its reciprocating motion in the axial direction, causes the flat enameled wire to be It is designed to peel off the insulation coating, and furthermore,
The insulating coating stripping device uses pulleys, for example two pulleys, that support a rectangular enameled wire stretched with appropriate tension, and the surface of the rectangular enameled wire stretched between these two pulleys. The flat enameled wire is provided with a rotating grindstone that is brought into contact with the wire so that it is slightly bent, and the insulating coating of the flat enameled wire is peeled off by the rotational movement of the rotating grindstone and, if necessary, its reciprocating motion in the axial direction. It is characterized by the fact that

[Effect]

As described above, in the method and apparatus for stripping the insulation coating of a rectangular enameled wire of the present invention, a rotating grindstone is brought into contact with the surface of the rectangular enameled wire stretched between two pulleys, and the rotating grindstone is rotated. Since the insulating coating of the rectangular enameled wire is peeled off by the movement, it is particularly suitable for forming electrodes of coils such as tapless coils using rectangular enameled wire, and it also prevents molten scum and combustion scum from adhering. To provide a method and an apparatus for peeling an insulating coating of a rectangular enameled wire, which can stably fix a coil such as a tapless coil on a printed circuit board, for example.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus for stripping an insulating coating of a rectangular enamelled wire according to the present invention will be described below with reference to FIGS. 1 to 5.

First, using Fig. 5 (A) to CD), flat enameled wire ■
I will explain about it. Recently, demands for smaller size and higher performance of electronic devices have been increasing year by year, and rectangular enamelled wire is attracting attention because it has a higher space factor for the conducting wire (conductor portion) than enamelled wire with a circular cross section.

The rectangular enamelled wire dish shown in Figure 2 has a square wire as shown in (A), a flat wire as shown in (B) and (C) of the same figure, and an ultra-thin wire as shown in (D) of the same figure. There are flat wires, etc.

In the same figure (D), two ultra-thin flat wires are bonded in parallel, and the thickness t of the conductor 32 can be made extremely thin, for example, about 20 μm, and the thickness t vs. width H can be made extremely thin. It is possible to make the ratio extremely flat, for example, down to 1 near 0.

Each of the rectangular enameled wires (2) has an insulating coating 33 coated on the outer periphery of the conductor 32, and further, as shown in the same figure (C), a fusion coating 34 is coated on the outer periphery of the insulating coating 33. There is also. Hereinafter, the insulation coating 33 is
In some cases, the insulation coating 33 is covered with the fusion coating 34.

Next, returning to FIG. 1, the rectangular enameled wire 31 (7
) Describe the method and equipment for removing the insulation coating.

In the drawing, 1 is a rotating grindstone, 2 is a first motor that rotates this rotating grindstone 1, 3a and 3b are pulleys, for example, two pulleys, and of these two pulleys, 3a is a movable pulley. , and 3b are fixed pulleys 0 For example, the number of movable and fixed pulleys 3a, 3b may be one or more, and is not particularly limited to two. Also,
One may be a pulley and the other simply a non-rotating guide.

Between these movable and fixed pulleys 3a and 3b, a rectangular enameled wire 31 (refer to FIG. 5 for rectangular enameled wire 3) is stretched with appropriate tension. This flat enamel wire■
The tension applied to is properly applied by a tension supply means (not shown).

Reference numeral 4 indicates an eccentric cam, and reference numeral 5 indicates a second motor that drives the eccentric cam 4. The rotary grindstone 1 is reciprocated in its axial direction (back and forth direction) by an eccentric cam 4 driven by a second motor 5. Reference numeral 6 denotes a rotating roller, and the rotating roller 6 contacts the eccentric cam 4 and rotates when the eccentric cam 4 rotates to reciprocate the rotating grindstone 1 in its axial direction. This is a roller that supports the reciprocating movement. And 7 indicates a tension spring. When the eccentric cam 4 driven by the second motor 5 causes the rotary whetstone 1 to reciprocate in its axial direction, the tension spring 7 holds the rotary whetstone 1 on its rear side (the rectangular enamel wire is stretched). (the side opposite to the side where the
give you the power to return to

Further, 8.9.10 indicates the first to third air cylinders. The first air cylinder 8 has movable and fixed pulleys 3a, 3
In order to set the rotary whetstone 1 from the axial direction on the rectangular enameled wire rainbow stretched between This is for moving back and forth in the axial direction.

The second air cylinder 9 is for vertically moving the rectangular enamel wire rod stretched between the movable and fixed pulleys 3a and 3b by vertically moving the movable pulley 3a.
Along with the vertical movement of the rotary grindstone 1, which is moved from below to above or from above to below, by the third air cylinder 10 described below, a slight deflection is applied to the rectangular enameled wire (), and the rectangular enameled wire () is rotated. This is for bringing the grindstone 1 into contact.

The third air cylinder 10 has movable and fixed pulleys 3a and 3b.
The rotary whetstone 1 is set by moving up and down on the rectangular enameled wire J2 stretched between (from bottom to top). Then, the rotary whetstone 1 is brought into contact with the rectangular enameled wire (2), and the insulating coating 33 made by the rectangular enameled wire company is peeled off by rotating the rotary whetstone 10 times. For this purpose, this third air cylinder 10
The sub-base 11 on which the first and second motors 2.5, the first air cylinder 8, etc. are mounted is moved in the vertical direction. 12 is a base, and this base 12 has a second
Substantially the entire device, including the air cylinder 9 and the third air cylinder 10 on which the sub-base 11 is placed, is placed and fixed.

Note that 13 is a winding frame of a winding machine which will be described later, and 14 is a clamper for the tip end 31a of the rectangular enameled wire J5.

The method of peeling off the insulating coating 33 of the rectangular enameled wire shadow of the present invention is to apply the rectangular enameled wire ... is brought into contact with the rotating grindstone 1 so that it is slightly bent, and the insulating coating 33 of the rectangular enameled wire is peeled off by the rotational movement of the rotating grindstone 1 and, if necessary, its reciprocating motion in the axial direction. This is a unique peeling method.

Reference numeral 32a shows the conductive wire after the insulating coating 33 on the back side, ie, the lower surface side, of the rectangular enameled wire (2) has been peeled off by an appropriate length lI.

In addition, the insulation coating 33 on the surface, that is, the upper surface side, has an appropriate length it.
Although not shown in this drawing, the conductive wire after being peeled off is designated as 32b. In addition, if necessary, use the rotating grindstone 1.
By causing the eccentric cam 4 driven by the second motor 5 to reciprocate in the axial direction, it becomes possible to more forcefully peel off the insulation coating 33 of the rectangular enameled wire (2).

Furthermore, the peeling device for the insulating coating 33 of the rectangular enameled wire (2) of the present invention includes pulleys, movable and fixed pulleys 3a and 3b, that support the rectangular enameled wire (2) stretched with an appropriate tension.
A rotary whetstone 1 is provided, which is brought into contact with the flat enameled wire J2 stretched between these movable and fixed pulleys 3a and 3b so that the rectangular enameled wire J2 is slightly bent. The insulating coating 3 of the rectangular enamelled wire bowl is
This peeling device is characterized in that it peels off 3.

Using such a method and apparatus, rectangular enameled wires from which the insulating coating 33 has been peeled off are adhered and fused to form a coil such as the tapless coil 21 shown in FIG. 2. Coils such as tapless coil 21 made of flat enamelled wire,
Even without particularly accurate traversing (feeding of the winding machine) of the rectangular enameled wire (2), it is possible to easily wind the wire in alignment by simply rotating the winding machine, for example. The portions of the conductive wires 32a and 32b obtained by peeling off the insulating coating 23 at the beginning and end of the winding of the coil such as the tapless coil 21 wound in this way by an appropriate length L and i2 are As shown in the figure, there are electrodes 21a and 21b at the beginning and end of winding.

As shown in FIG. 3, a coil such as the tapless coil 21 in which the winding start and winding end electrodes 21a and 21b are formed is attached diagonally to, for example, the circuit patterns 23 and 24 of the printed circuit board 22, that is, as shown in FIG. By soldering between the electrodes 21a and 21b at the start and end of winding and the circuit patterns 23 and 24, a coil such as the tapless coil 21 can be electrically and mechanically mounted and fixed on, for example, a printed circuit board 22. I can do it.

Next, using FIGS. 4(A) to 4(H), the insulating film peeling method and its apparatus of the present invention will be explained in more detail according to the process order. A winding frame 13 is provided at the rotating tip 13a of the winding machine, and the flat enameled wire rod has its tip 31a fixed to the clamper 14 so as to be in partial contact with the winding frame 13. A groove 15 is provided starting from the outer peripheral surface of the winding frame 13 and extending to the outer surface of the clamper 14 at the outer peripheral portion of the rotating tip 13a of the winding machine. The tip 31a of the rectangular enameled wire is inserted into the groove 15 and fixed to the clamper 14. Therefore, since the tip 31a of the rectangular enameled wire J2 does not protrude from the outer circumferential surface of the winding frame 13, the tip 31a of the rectangular enameled wire J2 can be seen from the rotation locus when the rectangular enameled wire is wound by the winding machine.
Since the tip part 31a escapes, the tip part 31a does not get in the way when winding is performed.

Adjust the insulation coating 33 on the back side of the rectangular enameled wire to an appropriate length! The conductive wire 32a after peeling by , becomes the electrode 21a at the beginning of winding shown in FIG. 2, but as shown in FIG. It is distinctive in that it is formed in the middle part, not the tip 31a, and by winding it, the tapless coil 2
For the first-class coil, the insulating coating 33 is peeled off so that the electrode 21a at the beginning of winding is on the inside thereof, that is, on the side of the winding frame 13.

In FIGS. 4(A) to (H), first, as shown in FIG. 4(A), the rectangular enameled wire
, 3b. The movable pulley 3a can be moved vertically by a second air cylinder 9,
Along with the movement of the movable pulley 3a, the rectangular enameled wire (2) stretched over the lower surface can be moved from below to above so as to avoid the rotating grindstone 1. As shown in FIG. 2B, the first air cylinder 8 moves the rotary grindstone 1 forward in its axial direction. As shown in the same figure (C),
The third air cylinder 10 moves the rotary grindstone 1 to the back side of the rectangular enameled wire ■, makes contact with the back surface, and the rotary whetstone 1 and movable pulley 3a bend the rectangular enameled wire bowl slightly. It will be done.

Appropriate tension is applied to this rectangular enamel line shadow 2 by a tension supply means (not shown).

The rotary grindstone 1 is rotated by the rotation of the first motor 2, and is further reciprocated in the axial direction by an eccentric cam 4 driven by the rotation of the second motor 5 as necessary, so that the grindstone 1 is rotated by the rotation of the first motor 2. On the back side of the wire bowl, the insulating coating 33 of the rectangular enameled wire as shown in FIG.
The conductive wire 32 after peeling is removed by an appropriate length.
form a. This conducting wire 32a becomes the electrode 21a at the beginning of winding, as described above. This peeling of the insulating coating 33 is carried out by the above-mentioned rotational movement of the rotary grindstone 1 and, if necessary, the reciprocating movement in the axial direction. By moving in the direction, it is possible to make a longer suitable length lI. However, it goes without saying that even if it is not moved in the longitudinal direction, it is possible to peel it off, although the length will be shortened. As shown in FIG. 2D, the first air cylinder 8 returns the rotary grindstone 1 to the rear side in the axial direction.

Next, the rectangular enameled wire (■) is wound around the winding frame 13 of the winding machine to form a coil such as the tapless coil 21 by a predetermined number of turns.
rotates when the rectangular enameled wire moves to the winding frame 13 of this winding machine, making it possible to send the rectangular enamelled wire to the winding frame 13 of the winding machine without difficulty. The rotation of the winding machine is stopped just before a predetermined number of windings are completed, and the insulating coating 33 on the surface side of the rectangular enameled wire (2) is peeled off by an appropriate length 12 to form a conducting wire 32b. The conducting wire 32b becomes the electrode 21b at the end of winding shown in FIG.

That is, as shown in FIG. 4(E), the movable and fixed pulleys 3a
, 3b, and the movable pulley 3a can be moved in the vertical direction by the second air cylinder 9, and as the movable pulley 3a moves, the rectangular enamelled wire (■) is stretched below it. It is possible to move the rectangular enameled wire ■ from the upper side to the lower side. As shown in FIG. 2F, the first air cylinder 8 moves the rotary grindstone 1 forward in its axial direction. As shown in the same figure (G), the third
By the air cylinder lO, the rotary whetstone l moves to the surface side of the rectangular enameled wire..., comes into contact with the surface, and the rotary whetstone l
and movable pulley 3a (and in addition, fixed pulley 3b)
The bending is applied so that the rectangular enameled wire (■) is slightly bent. This rectangular enameled wire is similarly given a separate appropriate tension as described above. The rotary grindstone 1 is rotated by the rotation of the first motor 2, and further reciprocated in the axial direction by an eccentric cam 4 driven by the rotation of the second motor 5 as necessary, and the stretched rectangular enameled wire is rotated by the rotation of the first motor 2. On the surface side of (2), the insulating coating 33 is peeled off by the rotational movement of the rotary grindstone 1 and, if necessary, the reciprocating movement in the axial direction. That is, as shown in FIG. 3H, the insulating coating 33 of the rectangular enameled wire 31 (7) is peeled off by an appropriate length lx to form a conductive wire 32b after the peeling. As described above, the conducting wire 32b becomes the electrode 21b at the end of winding.

After that, the winding machine is rotated a little further to wind the rectangular enameled wire ■ the predetermined number of turns, and the tapless coil 21
The completed coils, such as the tapless coil 21, are removed from the winding frame 13 shown in FIG. The rectangular enameled wire 2 is fixed by another clamper (not shown) provided in the holder. Then, between this other clamper and the winding frame 13, a flat enameled wire ■ is inserted.
Cut using a wire cutter (not shown). The rotating tip 13a of the winding machine located on the outer periphery of the winding frame 13
The coils such as the tapless coil 21 are removed from the winding frame 13 by moving the winding frame 13 forward (with the winding frame 13 fixed). Conductive wire 32a with subsequent insulation coating 33 peeled off
The tip portion 31a of the rectangular enamelled wire rod on which is formed is partially in contact with the winding frame 13 together with other clampers,
It is fixed to the clamper 14.

Through the above steps, a coil such as the tapless coil 21 as shown in FIG. 2 is completed. As shown in FIG. 3, the coils such as the tapless coil 21 are mounted and fixed by soldering, for example, to the circuit patterns 23 and 24 of the printed circuit board 22 and the like.

〔Effect of the invention〕

As explained above, the method and device for stripping the insulation coating of a rectangular enamelled wire according to the present invention, in which a rotary grindstone is brought into contact with the surface of a rectangular enameled wire stretched on a pulley, By peeling off the insulation coating of the enamelled wire, the following effects can be obtained.

b) It is particularly suitable for forming electrodes of coils such as tapless coils using rectangular enamelled wires.

Mouth) Since molten scum and combustion scum do not adhere, it is possible to stably mount and fix a coil such as a Tough Press coil on a printed circuit board without being disturbed by these molten scum or combustion scum. .

c) The insulation coating of the rectangular enameled wire can be peeled off quickly and evenly.

2) Since the conductor part is not damaged, disconnection accidents can be prevented and the influence on the conductor part can be reduced.

e) The configuration of the device is simple.

F) Since commercially available grindstones for rotary tools can be used, it is easy to obtain grindstones.

g) Correspondence to flat enameled wires with different specifications can be easily achieved by simply adjusting the amount of deflection of the flat enameled wire and the rotational speed of the rotary grindstone.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating the insulating coating peeling method and apparatus of the present invention. FIG. 2 is a perspective view of a tapless coil whose insulation coating has been removed by the method and apparatus of the present invention. FIG. 3 is a perspective view showing how the tapless coil shown in FIG. 2 is fixed to a printed circuit board. Figure 4 (A) to (
H) is a partially enlarged perspective view illustrating the method and apparatus of the present invention in the order of steps. Figures 5 (A) to (D) are cross-sectional views of rectangular enamelled wires, where (A) is a square wire, (B) is a flat wire coated with an insulating film, and (C) is an insulated wire. A flat wire coated with a coating and a fusion coating, and (D) an ultra-thin flat wire are shown. FIG. 6 is a perspective view of an enamelled wire with a circular cross section. FIG. 7 is a perspective view of the tapless coil. FIG. 8 is a perspective view showing how the tapless coil shown in FIG. 7 is fixed to a printed circuit board. FIG. 9 is a perspective view illustrating a conventional solder dipping method. FIG. 10 is a perspective view illustrating a conventional mechanical insulation coating peeling method. FIG. 11 is a perspective view illustrating a conventional method for peeling off an insulating film using heat from a laser beam. 1-m-one-rotation grindstone 2----------1st motor 3a, 3b
−・−・・−−～−−−−−Movable, fixed pulley 4−・−
...--Eccentric cam 5-----Second motor 6--
−−−−−・−・−・One rotation roller 7・−・・・−・・
-Tension spring 8.9.10・---～・Air cylinder 11−・・・
-・・・・・−Sub base 12−・−・・−・−1−−−−Base 13−・・・・−・・・Reeling frame 13a−・−−−−−− - rotating tip 14 of a single winding machine;
・−・・−・・−・−・Clamper 15−・−・・−
......Groove 21-----1...-Tapless coil 21a
, 21b...-- Electrode 22 at the start and end of winding
−・−・−・−・−・・Printed circuit board 23.24−・・
−−1−−−−・−Circuit pattern 31−・−・−−−
---1----Flat enameled wire 31a-----Front end portion of the rectangular enameled wire 32-----Conducting wires 32a, 32b...--Conducting wire after insulation coating has been peeled off 33-
・−・−・−・−・Insulating coating

Claims (2)

[Claims] 1. A rotary grindstone is brought into contact with the surface of the rectangular enameled wire stretched with appropriate tension on a pulley so that the rectangular enameled wire is slightly bent, and the insulating coating of the rectangular enameled wire is peeled off by the rotational movement of the rotary grindstone. A method for peeling an insulating coating from a rectangular enameled wire, which is characterized in that: 2. A pulley that supports a rectangular enameled wire stretched with appropriate tension, and a rotating grindstone that is brought into contact with the surface of the rectangular enameled wire strung on the pulley so that the rectangular enameled wire is slightly bent, 1. An insulating coating stripping device for a rectangular enameled wire, characterized in that the insulating coating of the rectangular enameled wire is stripped by the rotational movement of a rotary grindstone.