JPH01283904A - Method for fixing shading coil of electromagnet - Google Patents

Abstract

PURPOSE:To fix a shading coil rigidly, by forming recess parts which are wider than the widths of the opening part and the bottom surface part of a groove at both sides of the U-groove that is formed in an iron core, moving the body of the shading coil into the recess part of the groove by compression, and fixing the shading coil. CONSTITUTION:A U-groove 20 is formed for an iron core 1. Recess parts 23 which are wider than the opening part and the bottom surface part of the groove 20 are formed. A shading coil 2 is compressed with a compressing jig 24, and the body of the shading coil 2 is moved into the recess parts 23 of the groove. Thus, the shading coil 2 is fixed. Since the coil is compressed with the compressing jig 24 having the flat compressing surface, the coil is compressed without the escape of the body of the shading coil 2 toward the opening part of the groove 20. In this way, the body of the shading coil 2 can be embedded in the recess parts 23 on both sides of the groove 20 effectively, and the shading coil 2 can be fixed rigidly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for fixing a shaded coil of an AC electromagnet, and particularly to an AC electromagnet suitable for firmly fixing a shaded coil in a groove formed in an iron core. This invention relates to a method for fixing a shaded coil of an electromagnet.

[Conventional technology]

FIG. 21 is a partially cutaway side view of an AC magnetic contactor in which an electromagnet with a shaded coil fixed to an iron core is mounted.

The AC electromagnetic contactor shown in FIG. 21 includes an iron core 1, a shading coil 2 fixed to the core, a movable iron core 6, a coil 7, and a return spring 8.

In this AC magnetic contactor, when the coil 7 is energized.

The movable core 6 is attracted to the core 1 having the shaded coil 2 against the load force of the return spring 8 and the contact spring, and is polarized.

When the coil 7 is de-energized, it is configured to open into the state shown in FIG. 21.

This type of AC electromagnetic contactor has the opening/closing operation of 1000 times.
Performance that can be repeated 10,000,000 times is required, and the shaded coil 2 fixed to the iron core 1 also needs to have a fixing force that can withstand the collision force when the movable iron core 6 is connected 10,000,000 times.

Next, FIG. 22 is a side view showing the core to which the shading coil is fixed, FIG. 23 is a plan view thereof, and FIG. 24 is a perspective view showing the state before the core and the shading coil are fixed.

The iron plate 11 is made by laminating thin electromagnetic iron plates and fixed with rivets 3. Further, as shown in FIG. 24, two grooves 4 are formed in the iron core 1 on the side of the magnetic pole surface that is in contact with the movable iron core 6. A shading coil 2 is installed and fixed in this groove 4.

Next, FIGS. 25 to 39 are explanatory diagrams showing various conventional techniques for fixing a shaded coil to an iron core.

FIG. 25 shows a conventional technique (hereinafter referred to as "first conventional technique") in which a shaded coil is fixed to an iron core with adhesive. In this first conventional technique, a U-shaped groove 4 is formed in the iron core 1. Two shading coils 2 are formed, and the shading coils 2 are inserted into the grooves 4, and the shading coils 2 are bonded and fixed with an adhesive 5.

FIG. 26 shows a conventional technique (hereinafter referred to as "second conventional technique") disclosed in Japanese Unexamined Patent Publication No. 59-103313. In this second conventional technique, two grooves 4 are formed in the iron core 1. The shading coils 2 are formed so as to be inclined inward from each other, and the shading coil 2 is inserted into the groove 4 using a pressure jig 9 having a 7-shaped tip, and is then pressurized and fixed by the pressure jig 9.

27 to 29 show the prior art disclosed in Japanese Unexamined Patent Publication No. 58-145107 (hereinafter referred to as the "third prior art"), and FIGS. 30 and 31 show the third prior art.
In the conventional technique shown in FIG. 3, which shows the state in which the iron core and the shaded coil are deformed during the pressurization process according to the conventional technique, two U-shaped grooves 4 are formed in the iron core 1, and four grooves 4 are formed in the iron core 1.
A dogleg-shaped depression 10 is formed on both sides of the plate. and,
The shading coil 2 is inserted into the groove 4, and the shading coil 2 is pressed in the direction of arrow P by a pressing jig 9 having a 7-shaped tip. When the shading coil 2 is pressurized by the pressure jig 9, the tip of the pressure jig 9 bites into the shading coil 2, the shading coil 2 is expanded, and the flesh of the shading coil 2 is pressed into the depressions on both sides of the groove 4. 10, and the shading coil 2 is about to be fixed in the groove 4.

FIG. 32 and FIG. 33 show the prior art disclosed in Japanese Patent Publication No. 56-6612 (hereinafter referred to as the "fourth prior art"). In this fourth prior art, the iron core 1 has Two grooves 12 are formed whose bottom part is slightly wider than the opening part,
A chevron-shaped protrusion 13 is formed on the bottom surface of this groove 12.

Then, the shading coil 2 is inserted into the groove 12 using a pressing jig 4 having a flat pressing surface, and pressure is applied in the direction of arrow P. As a result, the bottom of the shading coil 2 is connected to the groove 12.
The shading coil 2 is fixed in the groove 12 by pushing it apart with the protrusions 13 and moving the flesh of the shading coil 2 to spread outward.

FIGS. 34 to 39 show another prior art (hereinafter referred to as the r-th fifth prior art J). In this fifth prior art,
Two U-shaped grooves 4 are formed in the iron core 1, arc-shaped recesses 15 are formed on both sides of the four grooves 4, and a shading coil is inserted into the grooves 4. Next.

As shown in FIG. 36, the inclined surface of a pressing jig 17 having a sloping surface in the shape of a diagonal is brought into contact with the outer core portion 16 of each of the two grooves 4, and the pressing jig is The tool 17 is moved in the direction of arrow P. As a result, the outer core portions 16 of the two grooves 4 are bent inward using the pressing jig 17, and the shading coil 2 is sandwiched and fixed within the grooves 4. When the outer core portion 16 of the groove 4 is bent, a step G is created between the center core portion between the two grooves 4 and the outer core portion 16, as can be seen from FIGS. 37 and 39. . Step G on the magnetically contacting surface of core 1
If there is a
The step G is removed to create a flat surface.

[Problem to be solved by the invention]

The first conventional technology among the above-mentioned conventional technologies is based on the reliability of whether opening and closing operations can be repeated more than 10 million times when an AC electromagnet manufactured by this technology is used in, for example, an AC magnetic contactor. There is a problem of lack of. Furthermore, this first conventional technique has a problem in that it is difficult to rationalize the work.

The second prior art and the third prior art are as follows.

Since the pressure jig 9 having a 7-shaped tip is used, it is inevitable that a 7-shaped indentation will remain on the magnetic pole surface side of the shading coil 2 where the movable iron core is brought into contact with the iron core 1.

There is a problem in that this has a large negative effect on the performance as an AC electromagnet. Furthermore, even if the shading coil is pressurized with the pressure jig 9 having a 7-shaped tip, as can be seen from FIGS. The groove 4 is pushed open by the 7-shaped tip of the pressing jig 9.
, and then the meat of the shading coil 2 escapes to the opening side of the groove 4 and swells up. therefore.

In particular, in the third prior art, the flesh of the shading coil 2 does not move sufficiently into the dogleg-shaped depressions 10 formed on both sides of the groove 4, and the shading coil 2 does not move sufficiently into the depression 1o, as shown in FIG. I can't fill up the meat. Therefore, the second and third
The prior art has a problem in that the fixing force of the shading coil 2 to the groove 4 of the iron core 1 is weak.

The fourth prior art has a problem in that the shape of the groove 12 is complicated and that forming the groove 12 requires a lot of time and equipment.

In the fifth prior art, the iron core 1, which is a laminate of hard thin plates, is bent in the width direction of the plates, which is difficult to bend, so it is easy to buckle, and as shown in FIG. 4, the outer core part 16 falls down, and the magnetic pole surface shifts,
There is a problem that the clamping force of the shading coil 2 becomes unstable. Further, as shown in FIG. 36, when the inclined surface of the pressing jig 17 is used to tilt down the core portion 16 outside the groove 4, there is a problem in that wear of the pressing jig 17 must be taken into account. There is. Moreover, after knocking down the iron core portion 16 outside the groove 4,
The central core portion between the grooves 4 and the core portion 16 outside the grooves 4
There is also the problem that it is necessary to grind the step G in between, which requires a process and equipment. Furthermore, as shown in FIG. 37, the fallen core portion 16 outside the groove 4 tries to recover elastically in the direction of the arrow in the figure, but since the modulus of elasticity of the shaded coil 2 is smaller, the pressure is applied. There was a problem in that the clamping force of the shading coil 2 decreased after the jig 17 was removed.

An object of the present invention is to solve the problems of the prior art, to firmly fix a shaded coil in a groove formed in an iron core, and to improve the quality and performance of an AC electromagnet.
Moreover, it is an object of the present invention to provide a method for fixing a shaded coil of an AC electromagnet, which can be reliably processed with simple equipment and a small number of man-hours.

[Means to solve the problem]

The purpose is to form concave portions on both sides of a U-groove formed from the magnetic pole face of the iron core toward the inside, the width of which is wider than the groove width of the opening and bottom portion of the groove, and to form a shading in the groove. Insert the coil, pressurize this shaded coil from the opening side of the groove toward the bottom side using a pressurizing jig with a flat pressurizing surface,
Move the meat of the shaded coil to the recessed part of the groove and embed it.
This is achieved by fixing the shading coil to the iron core through the flesh of the shading coil embedded in the recessed portion of the groove.

[Effect]

In the present invention, a shading coil is inserted into a U-shaped groove in an iron core with concave portions formed on both sides of the groove.

Next, this shaded coil is pressurized from the opening side of the groove toward the bottom surface using a pressurizing jig having a flat pressurizing surface.

As a result, the shading coil is plastically deformed, and the flesh of the shading coil moves into the recesses formed on both sides of the groove.

As a result, the thickness of the shading coil is embedded in the recessed portion of the groove, and the shading coil is fixed within the groove of the iron core by the recessed portion of the groove and the thickness of the shading coil embedded therein.

As mentioned above, in the present invention, the shading coil is pressurized with a pressurizing jig with a flat pressurizing surface, so that the meat of the shading coil is pushed into the groove without escaping to the opening side of the groove. The meat of the shading coil can be effectively embedded in the recessed part of the shading coil, and when the shading coil is pressurized, the outer core part of the Zendo will fall down slightly, and when the pressing jig is pulled out of the groove, Since the outer core portion of the lead returns due to springback and tightens the shading coil, the shading coil can be firmly fixed within the groove of the core.

In addition, in the present invention, since the shaded coil is pressurized with a pressure jig with a flat pressure surface, there is no impression left on the magnetic pole surface side of the iron core in the shaded recoil, and the core portion outside the groove is bent. Since there is no need to knock it down, the quality and performance of the AC electromagnet can be improved.

Furthermore, in the present invention, the shape of the groove is relatively simple and easy to process, and equipment for tilting the core outside the groove and grinding the step between the core part in the center between the grooves and the core part outside the groove. Since no process or equipment is required, processing can be performed reliably with simple equipment and a small number of man-hours.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 5 are diagrams showing an embodiment of the present invention in the order of steps, and Figures 6 (A) and (B) show how to straighten the shaded coil using a pressing jig with a flat pressing surface of the pressing section. FIG. 7 is an explanatory diagram showing the deformation state of the shading coil when it is pressurized, and FIG. 7 is an explanatory diagram showing the shape of the groove formed in the iron core, the pressing force, and the movement state of the shading coil.

FIGS. 8(A) and 8(B) are diagrams showing the specifications of the groove and the shaded coil.

In the method of fixing the shading coil of the embodiment shown in these figures, first, as shown in FIG. 1, two grooves 20 are formed in the iron core 1 at a predetermined interval.

The groove 20 is formed in a U-shape from the magnetic pole surface of the iron core 1 toward the inside, and a recessed portion 23 having a width wider than the opening 21 of the groove 20 and the groove width of the bottom portion 22 is formed on both sides of each portion 20. It is formed. In this embodiment, the recessed portion 23 is 0.
is formed.

The dimensions of each part of the groove 20 are shown in Figure 8 (
When it is defined as shown in A), - For example, do the following.

d=0.7mm D=1.1mm w=0.8mm
050.2 mm Next, as shown in FIG. 2, the shading coil 2 is inserted across the two grooves 20.

The dimensions of the shading coil 2 are as follows, assuming that the dimensions of each part of the groove 20 are as described above and the specifications of each part of the shading coil 2 are determined as shown in FIG. 8(B). Make it.

h = 1.8 mm t = 0.8 mm In order to shorten the magnetic path and control loss, it is better to have a smaller space between the groove opening side surface of the shaded coil fixed under pressure and the armature surface.

It is desirable that (D+d) −h'<0.5 mm and s'>2s.

However, S: Area of the concave portion of the groove 5': Area of the portion corresponding to the rIi coil (hh'). As an example, h' is set to 1.4 mm.

Next, as shown in FIGS. 3 and 4, the pressure jig 2 is
4 pressurizes the shading coil 2. The pressure jig 24
The pressure surface 25' of the pressure section 25 is formed flat and has a width as wide as possible to allow insertion into the groove 20.

6(A), (
As can be seen from B), the meat of the shaded coil 2 moves,
It expands into a drum shape. The present invention is based on this knowledge.

When the shading coil 20 is pressurized by the pressing jig 24, as shown in FIG. Pressed by the reaction force r on both sides, the shading coil 2 is plastically deformed.

When the shading coil 2 is pressurized and deformed, the fifth
As shown in the drawings and FIG. 7, a portion of the meat of the shading coil 2 is embedded in the recesses 23 formed on both sides of the groove 20. As shown in FIG. Note that at this time, the groove 20
The outer core part of is suppressed and escapes slightly to the outside.

After the flesh of the shading coil 2 is completely embedded in the concave portion 23 of the groove 20, the pressing jig 24 is pulled up and one stroke of processing is performed to fix the shading coil 2 in the groove 20 formed in the iron core 1. end.

After applying pressure to the shading coil 2 and moving a part of its flesh into the recessed part 23 of the groove 20 and embedding it.

When the pressing force is released, the core portion outside the groove 20 returns to its original state due to springback, tightening the shading coil 2 within the groove 2°. Thereby, the shaded coil is held even more firmly.

FIGS. 9(A) and 9(B) are sectional views showing a comparison between a shading coil fixed according to the prior art and a shading coil fixed according to the embodiment of the present invention.

The prior art shown in FIG. 9(A) corresponds to the third prior art, and since the pressurizing part applies pressure with a 7-shaped pressurizing jig, the iron core 1 in the shaded coil 2 A figure 7-shaped indentation remains on the magnetic pole surface side, which has a negative effect on the performance of the AC electromagnet.Furthermore, the dog-shaped depressions 10 formed on both sides of the groove 4 are similar to those of the lover 1. is small, and when the shading coil 2 is pressurized with a pressure jig with a 7-shaped pressurizing part, the flesh of the shading coil 2 swells toward the opening of the groove 4 and escapes, causing the depression of the groove 4. 10, the meat of the shaded coil 2 does not move sufficiently. Therefore, in this third prior art, the fixing force of the shading coil 2 is weak against the collision force when the movable iron core 6 is polarized.

On the other hand, in this embodiment of the present invention shown in FIG.
Since the pressurizing jig 24 is applied with a large □ and a flat pressurizing surface 25', the flesh of the shaded coil 2 can be sufficiently moved and embedded in the concave portion 23 of the groove 20. Therefore, the fixing force of the shaded coil 2 against the collision force when the movable iron core 6 is polarized can be strengthened.

Moreover, since the magnetic pole surface side of the iron core 1 in the shaded coil 2 after pressurization is flat and no figure 7-shaped impression is formed, it is possible to improve the quality and performance of the AC electromagnet.

Next, FIGS. 10, 11, and 12 are enlarged views showing various embodiments with different shapes of recesses.

In the embodiment shown in FIG. 10, the concave portion 26 is formed into a gentle arc shape.

In the embodiment shown in FIG. 11, the concave portion 27 is formed into a gentle dogleg shape.

In the embodiment shown in FIG. 12, the concave portion 28 is formed in a shape that is a combination of a shoulder portion, a vertical portion, and a tapered portion whose spacing gradually decreases toward the bottom portion 22. In the embodiment shown in FIG.

The recessed portions 26, 27, and 28 are similar to the recessed portion 23 shown in FIG. The 5 functions are almost the same.

Next, FIG. 13 is a diagram showing another embodiment of the present invention in which the shape of the pressing jig is different.

The pressing jig 29 shown in FIG.
1.

Two of the pressing parts 30 are provided corresponding to the grooves 20, similar to the pressing parts 25 of the pressing jig 24 shown in FIG.
The pressure surface 30' is formed flat.

The iron core portion fall prevention portions 31 are provided on both sides of the iron core 1 in the width direction, and are formed with a slight gap between them and the iron core portion outside the groove 20 in the iron core 1.

The iron core portion fall prevention portion 31 blocks the iron core portion outside the groove 20 from falling excessively outward when the shading coil 2 is pressurized. As a result, the pressurizing force acts effectively on the shading coil 2, so the shading coil 2
can be fixed efficiently.

FIG. 14 is a cross-sectional plan view of the shading coil being pressurized and fixed in the groove, and FIG. 15 and FIG. It is a perspective view showing an example.

As explained in the section of the prior art, the iron core 1 is constructed by laminating thin electromagnetic iron plates and fixing them with rivets. Since each electromagnetic iron plate is formed by being punched out using a press, there are always breaks on the sheared surface. Therefore, by stacking these electromagnetic iron plates, the grooves 4 formed in the iron core 1 have 14
As shown in the figure, a recess 32 is formed in the mating surface of the electromagnetic iron plate. When the shading coil 2 is pressurized within the groove 20, the flesh of the shading coil 2 also moves into the recess 32 of the recess 23 of the groove 20, as shown in FIG. The shaded coil 2 can be fixed even more firmly.

In addition, as shown in FIG. 15, by actively forming a notch 33 on the mating surface of the electromagnetic iron plate in the groove 20,
It becomes possible to fix the shaded coil 2 even more firmly in the groove 20.

Furthermore, as shown in FIG.
When the iron core 1 is constructed by adding an electromagnetic iron plate 34 formed with a chisel, the shading coil 2 can be fixed even more firmly in the groove 20 due to the blocking action of the electromagnetic iron plate 34 as an end plate of the iron core 1.

17 to 20 are diagrams showing various test results of AC electromagnets having shaded coils fixed by the method of the present invention and AC electromagnets having shaded coils fixed by other methods. .

As shown in FIG. 17, in the case where the groove is formed in a U-shape and in the case where O-shaped recesses are formed on both sides of the U-shaped groove, as in one embodiment of the present invention, It can be seen that the mechanical life of the shaded coil is very good in this embodiment of the invention.

Also, as shown in FIGS. 18 and 19.

When pressurizing a shaded coil with a pressure jig with a pressure section shaped like a 7 (indicated as "V caulking" in the figure), and when applying pressure with a flat pressure surface of the pressure section. In the case of the present invention in which the shaded coil is pressurized with a jig (indicated as "flat caulking" in the figure), the amount of deformation of the core near the opening of the groove is greater in the former than in the latter. It turns out it's much bigger. The fact that the amount of deformation of the core near the groove opening is large means that the groove opening expands in the axial direction, so when the shaded coil is pressurized, the flesh of the shaded coil is pushed closer to the groove opening side. It means to get excited and run away.

Therefore, with the conventional technique of applying pressure to the shading coil using a pressurizing jig with a 7-shaped pressurizing part, even if a concave part or recessed part is formed on the side surface of the groove, the meat of the shading coil may not be sufficiently filled into this. I understand. On the other hand, in the present invention, since the pressing surface of the pressing jig is formed flat, the meat of the shading coil can be reliably moved and filled into the recesses formed on both sides of the groove.

Furthermore, as shown in Fig. 20, concave parts are formed on both sides of the groove of the core, and when a shading coil is inserted into the groove and pressurized with a pressurizing jig, the pressurizing surface of the pressurizing part becomes flat. In the case of a pressurizing jig that has been formed, the flesh of the shaded coil can be embedded in the recessed part with a pressurizing force of 2 x 1000 kg, but in the case of a pressurizing jig that has a pressurizing part shaped like a 7, 2xlOOOO
It can be seen that the flesh of the shaded coil cannot be filled into the concave portion with a pressing force of kg.

〔Effect of the invention〕

According to the present invention described above, recessed portions having a width wider than the groove width of the opening and bottom portion of the groove are formed on both sides of the U groove formed inward from the magnetic pole face of the iron core, Since the shading coil is inserted into the groove and the shading coil is pressurized with a pressure jig with a flat pressure surface, the meat of the shading coil is pushed into the opening side of the groove without escaping. , the meat of the shading coil can be effectively filled into the recesses on both sides of the groove, and when the shading coil is pressurized, the outer core of the lead will fall down slightly, and the pressing jig will be pulled out of the groove. When this happens, the outer core portion of the guide springs back and tightens the shading coil, which has the effect of firmly fixing the shading coil within the groove of the core.

Further, according to the present invention, since the shading coil is pressurized using a pressing jig with a flat pressing surface, there is no impression left on the magnetic pole surface side of the iron core in the shading coil, and the iron core outside the groove is Since there is no need to bend the parts, the quality and performance of the AC electromagnet can be improved.

Furthermore, according to the present invention, the shape of the groove is relatively simple and easy to process, and the equipment for tilting the core on the outside of the groove and the difference in level between the core part in the center between the grooves and the outside part of the groove can be eliminated. Since a grinding process and equipment are not required, the process can be reliably processed with simple equipment and a small number of man-hours.

[Brief explanation of the drawing]

Figures 1 to 5 are diagrams showing an embodiment of the present invention in the order of steps, and Figures 6 (A) and (B) show that the shaded coil is straightened using a pressing jig with a flat pressing surface of the pressing part. An explanatory diagram showing the deformation state of the shading coil when pressurized, FIG. 7 is an explanatory diagram showing the shape of the groove formed in the iron core, the pressing force, and the movement state of the shading coil meat, FIG. 8 (A), (B) is a diagram showing the specifications of the groove and the shading coil, and FIGS. 9(A) and 9(B) are the shading coil fixed by the prior art and the implementation shown in FIGS. 1 to 8 of the present invention. 10, 11 and 12 are enlarged views showing various embodiments with different shapes of groove recesses, and FIG. 14 is a cross-sectional plan view of the shading coil being pressurized and fixed in the groove; FIGS. 15 and 16 are views showing other embodiments of the present invention in which the pressure jig has a different shape; FIG. 17 to 20 are perspective views showing other embodiments of the present invention that utilize the sagging of the electromagnetic iron plate constituting the iron core, and FIGS. 17 to 20 respectively show an AC electromagnet having a shaded coil fixed by the method of the present invention, FIG. 4 is a diagram showing various test results with an AC electromagnet having fixed shaded coils by other methods. Fig. 21 is a partially cutaway side view of an AC magnetic contactor equipped with an electromagnet with a shading coil fixed to the iron core, Fig. 22 is a side view of the iron core with a shading coil fixed to it, Fig. 23 is a plan view of the same, and Fig. 24 The figure is a perspective view showing the state of the iron core and the shaded coil before they are fixed. FIG. 25 is a partially cutaway side view showing the first prior art;
FIG. 6 is a partially cutaway side view showing the second prior art, FIGS. 27 to 29 are views showing the third prior art, and FIGS. 30 and 31 are pressurizing processes according to the third prior art. Figures 32 and 33 are diagrams showing the fourth prior art, and Figures 34--
FIG. 39 is a diagram showing the fifth prior art. DESCRIPTION OF SYMBOLS 1... Iron core, 2... Shading coil, 20... Groove formed in the iron core, 21... Opening of the groove, 22... Bottom of the groove, 23... Both sides of the groove a recess formed in the
24... Pressure jig, 25... Pressure part of the pressure jig, 2
5'...Flat pressurizing surface of the pressurizing part, 26-28...Concave portions of various shapes formed on both sides of the groove, 29...
Pressure jig, 30... Pressure part of the pressure jig, 30'...
Flat pressurizing surface, 31: Fall prevention part of iron core part. 3rd Kuchi 4-Diagram section firA-A $b diagram (A) (B) Fig. 7 Li 3L (A) Toki I (A) (E3) Kuchi (B) Toki IoT2:J No. 111 Fig. 12 City r4. ) 73 15th Shi] $/Otsu Figure pigeon 20 Figure kudzu 21 Figure $z4-121 825 Figure 26 Figure 32 833 Figure % 3+s 蘂 35 Figure cross section 0-〇

Claims (1)

[Claims] 1. On both sides of a U-groove formed from the magnetic pole surface of the iron core toward the inside, recesses having a width wider than the opening and bottom of the groove are formed, and a shading coil is inserted into the groove. , Pressure is applied to this shading coil from the opening side of the groove toward the bottom side using a pressure jig with a flat pressing surface, and the meat of the shading coil is moved and embedded into the recessed part of the groove, and the shading coil is pressed into the recessed part of the groove. A method for fixing a shaded coil of an AC electromagnet, characterized by fixing the shaded coil to an iron core through the flesh of the shaded coil embedded in the shading coil.