JPH0361935A - Opening/closing blade driving device and production thereof - Google Patents

Abstract

PURPOSE:To reduce the number of parts and to make the whole size of device compact by using an insulator formed by a center connection part for covering the opening/closing blade side end face of a coil frame and insulating chips connected to both the sides of the center connection part to cover the side faces of coils. CONSTITUTION:An insulating means for securing insulation between the 56, 57 and yokes is a flexible insulating material 80 formed by the center connection part 81 constituting the center part and the insulating chips 82 extended to both blades to cover the sides of the coils like an insulating shape. The yokes cover the coil side faces so as to follow the insulating chips 82 along their insides. Since the insulating property of the insulator 80 is secured by covering also the end face of the rotational axis side of a rotor in addition to the side faces of the coils, the insulator 80 can be fixed to the bottom board e.g. of the opening/closing blade without requiring a fixing cover or the like. Consequently, the number of parts can be reduced and the opening/closing blade drive with compact constitution can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an opening/closing blade drive device for driving opening/closing blades of, for example, a video camera, and an improved manufacturing method thereof.

[Prior Art] The configuration of a conventional opening/closing blade drive device 100 is shown in FIGS. 13 and 14.

In the device 100, a pair of upper and lower bearings rotatably sandwich a rotor 101 having a rotating shaft 101a between coil frames 102 and 103 around which coils 102a and 103a are wound, through washers 104 and 105. cover 108
Insert. Then, the concave portion 102 of the negative coil frame 102
A detection element 113 for detecting the rotational position of the rotor 101 and its lead wire 114 are attached to b, and then in order to maintain the insulation properties of the coils 102a and 103a, which are wound around the coil frame, each coil 102a, 103a
Adhesive tape 109, 109 is applied to cover the side surface of the coil frame 102, 103, and the cylindrical yoke 106 is fitted from above, and then the mounting cover 10 is placed from above the coil frame 102, 103.
Attach 7.

An operating lever 111 for operating, for example, an opening/closing blade of a camera is attached to the rotating shaft 101a of the rotor 101, and a biasing spring 110 for biasing the operating lever 111 in one direction is provided. Further, on the lower surface of the cover 108, lead wires 115 of the coils 102a and 103a are provided.
is attached, and the device 100 thus produced is attached to, for example, the base plate 112 of the opening/closing blade of a camera.

Further, the detection element 113 is connected to the coil frame 1 as shown in FIG.
It is housed in the recess 102b of 02.

That is, the printed board 114a at the terminal of the lead wire 1]4
is adhered to the recess 102b with an adhesive, and the detection element 113 is adhered thereon.

[Problems to be Solved by the Invention] However, in such a conventional opening/closing blade drive device, the bearings are attached to the washers 104, 105 and the mounting cover 107.
The number of parts such as
7a, a large installation space is required, and there is a problem in that the request for miniaturization is discouraged.

Furthermore, insulating adhesive tape 109.10 is used to ensure insulation between the coils 102a, 103a and the yoke 106.
9 is difficult to handle, and even if the assembly process of other parts can be automated, it is difficult to automate this part. Conventionally, it has been necessary to rely on manual labor or to devise extremely complicated and expensive equipment even if automation was possible. I had to.

Furthermore, when attaching the magnetic detection element 113, it must be attached to the recess 102b of the coil frame 102 using an adhesive, which is troublesome and time-consuming.

[Purpose of the Invention] The present invention has been made in view of the problems in the conventional technology as described above, and provides an opening/closing blade drive device with a very small number of parts and a compact configuration, and is easy to handle. The purpose of the present invention is to provide a method for manufacturing an opening/closing blade drive device that does not use troublesome adhesive tapes, is easy to automate, and is low cost.

[Means for Solving the Problems] The opening/closing blade drive device of the first invention of this application includes a rotor having a rotating shaft that transmits a driving force to the opening/closing blades, a pair of coil frames that sandwich the rotor, and a pair of coil frames that sandwich the rotor. An opening/closing blade drive device comprising coils wound around a coil frame, and a yoke that protects these coils with insulating means and fits the pair of coil frames inside, wherein the insulating means is flexible. The coil frame has a central connecting part that covers the end face of the opening/closing blade side of the coil frame, and insulating pieces are formed on both sides of the central connecting part to cover at least both sides of the coil. It is a feature.

Further, the insulator of the opening/closing blade drive device according to the first aspect of the invention is characterized in that it is made of a translucent material.

A third invention of this application is an invention of a method for manufacturing the opening/closing blade drive device, which includes a central connecting portion that is the center;
On both sides of this central connection part, a flexible insulating tape material is placed in which a large number of insulators consisting of at least insulating pieces covering both sides of the coil are arranged adjacently, and can be fed out according to the assembly tact. a step of supplying a pair of coil frames and winding the coil; a step of rotatably holding a rotor formed by passing a rotating shaft through a magnet inside these coil frames; There is a cylindrical shape on the outer periphery of this coil frame that houses the rotor,
The process consists of a step of extrapolating a yoke constituting a magnetic path, and during this yoke extrapolation step, the insulating tape material is overlapped at a predetermined position on the coil frame, and then the yoke is placed on the rotating shaft side. The insulating tape material is pressed from the yoke, and the insulator is separated from the insulating tape material by the pressing force of the yoke, and one end surface of the coil frame is attached to the central connection part, and the coil is attached to the insulating piece along the inner circumference of the yoke. Make sure to cover the sides of the

[Function] The insulating means for ensuring insulation between the coil and the yoke is a visible insulating material, which extends to the central connecting part forming the center part and both wings thereof, and covers the sides of the coil. It is an insulator formed on a covering insulating piece.

The yoke serving as a yoke covers the side surface of the coil with the insulating piece along its inner surface.

In this way, the insulator covers not only the side of the coil, but also the end face of the rotor's rotating shaft to ensure insulation, so there is no need for a mounting cover, and it can be attached directly to the ground of the opening/closing blade, for example. Is possible.

Since this insulator is translucent, it is possible to see through the internal coils from the rotating shaft side of the rotor through the central connection part, and to know the function of each coil, that is, whether it is a driving coil or a braking coil. This makes it possible to avoid errors when attaching the rfR closed blade to the blade side or attaching lead wires.

Next, regarding the manufacturing method of the drive device, a large number of the insulators are arranged adjacent to each other on a long thin tape using, for example, a punching method. That is, each #! The central connecting portion of the edge is arranged along the center line of the tape, and the insulating strips extend from the central connecting portion toward both side edges of the tape. The outer end of each edge piece is formed into a narrow cut portion so that it can be easily cut from the tape. Further, the connecting portion between the central connecting portion and both line edge pieces is also knitted so that it can be easily bent.

In this way, an insulating tape material formed by connecting a large number of insulators along the longitudinal direction can be wound around a reel, for example.
It is designed to be unrolled according to the tact of the assembly process.

On the other hand, the coil frames are sent pair by pair through a process of winding the coils, and sent to a process of sandwiching a rotor having a rotating shaft.

In the above process, the rotor is rotatably held between the coil frames, and in the next process, a yoke is fitted onto the coil frame with an insulator in between.

In the process of externally fitting this yoke, first, the assembly of the rotor and coil frame made in the previous process is supplied below the stretched insulating tape material, and then The rotating shaft of the rotor is inserted through the tape material.Then, a yoke is brought close to the tape material so that its center line coincides with the rotating shaft, and the insulator in the tape material is pressed by the tip edge of the yoke. The inner circumferential diameter of the cross section perpendicular to the axis of the yoke is made to exactly correspond to the outer circumferential shape of the central connection part of the insulator, and the insulating piece of the insulator can be easily cut from the tape material. The insulator is separated from the tape material by the pressure applied by the yoke. Then, both wire edge pieces are bent at the central connecting part, and as they are, they cover the sides of the coil that is wound around the coil frame along the inner surface of the yoke, and the yoke is wrapped around the outer circumference of the coil frame with the insulator sandwiched inside. to fit.

The above-mentioned yoke fitting operation may be performed one by one, but it is also possible to arrange a large number of coil frames holding the rotor in tandem, and to simultaneously fit the yokes corresponding to each pair of coil frames to the respective coil frames. It is also possible.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, the configuration of the opening/closing blade drive device will be explained based on FIG. 1.

In this embodiment, an example in which the present invention is applied to a diaphragm device S of a camera will be described.

Shibori outfit! S consists of an aperture blade mechanism section 10 equipped with opening/closing blades (aperture blades) 11.12, and a drive device 50 that is attached to the main plate 20 of this aperture blade v1 elliptical part 10 and drives the blades 11.12. There is.

The base plate 20 of the aperture blade mechanism section 10 includes a drive mounting section 21 to which a drive device 50 is attached, and a blade mounting section 22 in which a light receiving aperture 23 is formed.

The base plate 20 is designed to prevent static electricity generated by friction between the aperture blades 11.12 or between the aperture blades 11.12 and the base plate 20 or a presser plate 30 (described later) when the aperture blades 11.12 are opened and closed. Flow to the main body side, aperture blade 1
1.12 together or aperture blade 11.12 and main plate 20
Alternatively, in order to prevent sticking due to static electricity generated between the presser plate 30 and the aperture blades 11 and 12 to open and close smoothly, at least when molding the base plate 20, the molding material itself is conductive so as to obtain conductivity. Either by selecting the material or by adding, for example, a carbon material to the molding material. In addition, in the case of sheet metal molding, surface treatment that provides conductivity may be performed.

The drive mounting portion 21 includes a shaft hole 24 through which the rotating shaft 53 of the drive device j50 is inserted, and a mounting hole 26 through which the screw 25.25 is inserted.
26 and a small hole 27 for mounting and positioning the drive device 50.

The aperture blade 1 is attached to the blade attachment part 22 with the light receiving aperture 23 in between.
Guide pins 28 and 29 are implanted to guide 1.12.

The aperture blade 11 is provided with an aperture opening 13, a guide groove 14 that slidably engages with a guide pin 28, and a pivot hole 15 that pivots on an operating pin 63a of an interlocking arm 62, which will be described later.

The diaphragm blade 12 includes a half-moon-shaped diaphragm opening 16, a guide groove 17 that is slidably engaged with a guide pin 29, and an interlocking arm 62.
A pivot hole 18 is provided for pivotally supporting the operating bin 63b.

Further, on the base plate 20 in which the aperture blades 11 , 12 and the interlocking arm 62 of the drive device 50 are housed, a substantially identical restraining plate 30 is provided to cover the entire surface of the base plate 20 .

The holding plate 30 has a hole corresponding to the light receiving aperture 23 of the main plate 20.
A light-receiving opening 31 is drilled therein, and guide grooves 32, 33 of the linkage arm 62 for guiding the operating pins 63a, 63b of the linkage arm 62 of the drive device 50 are also drilled therein. Note that this holding plate 30 is attached to the hook 20a on the main plate 20 side.
, 20b, 20C, etc., the hook locking holes 30a, 30b, 30c, etc. on the holding plate 30 side are locked to the main plate 20.
is combined with

The drive device 50 has a rotating shaft 53 at the center of a cylindrical magnet 52.
a pair of coil frames 54.55 that rotatably sandwich the rotor 51, and coils 56.57 wound around these coil frames 54.55.
A terminal plate 59 that connects the ends of these coils 56 and 57 to the lead wire 58, a yoke 60 that surrounds the outer periphery of the coil frame 54 and 55 and serves as a yoke that guides the magnetism of the magnet 52 of the rotor 51, and this yoke. 60 and said coil 56°5
7 and an insulator 80 to ensure insulation from the side surfaces of 7.

Further, the rotating shaft 53 of the rotor 51 is inserted into the shaft hole 20 of the base plate 20.
An interlocking arm 62 that engages with the aperture blades 11 and 12 is provided at the end passing through the aperture blades 11 and 12, and is biased by a spring 64 in one direction l11 (counterclockwise in FIG. 1). The operating bin 63a on the arm 62 is the aperture blade 1
Similarly, the operating pin 63b is connected to the pivot hole 15 of the aperture blade 1.
They are pivotally connected to the two pivot holes 18, respectively.

When the coil frames 54 and 55 are combined, the outer circumferential shape of the section perpendicular to the axis is formed into a circular shape, and the coil frames 54 [11] are provided with engaging protrusions 65 in order to connect them to each other. However, an engagement hole 66 is provided in the base surface of the coil frame 55. When the two coil frames 54 and 55 are combined, they form a pair of positioning protrusions that fit into the positioning holes 27 and 27 of the base plate 20. A positioning protrusion 67 is provided in a protruding manner.

Moreover, holes 54a and 55a are provided in the upper and lower center portions of the bearings for pivotally supporting the rotating shaft 53 of the rotor 51.

Further, screw holes 68 are provided into which screws 25.25 are screwed in when attaching the coil frame 54.55 to the base plate 20. In this way, the coil frame 54.55 can be directly attached to the main plate 20 as shown in FIG. 4 using the screws 25.25, so there is no need for the mounting cover 107 as shown in FIG. , the installation height can also be made very low.

The coil frame 54.55 is provided with a coil shaft for winding the coil 56.57 in the axial direction, and a pair of terminal pins 69.69 are provided at the bottom for winding the ends of the coils 56.57. is press-fitted.

The tip of these terminal pins 69... is the coil 56.57.
The terminal of the lead wire 58 is soldered.

Further, a concave portion 71 is provided in the body of the coil frame 54, 55 to accommodate a magnetic detecting element 70 such as a Hall element for detecting the phase angle of the rotor 51, and a recess 71 corresponding to the magnetic detecting element 70 is provided. A through hole is provided in the section.

As shown in FIG. 5(a), a pair of small protrusions 71a are protruded from the recessed portion 71, and the magnetic detection element 70 and the printed board 61a at the end of its lead wire 61 are bonded together. It can be installed without any medicine. The magnetic detection element 70 and the printed board 61a are shown in FIG. 5(b).
It is also possible to attach it in the opposite direction, as in

The terminal plate 59 is formed into a circular shape by a flexible material such as epoxy resin containing glass fiber, and has four small holes 59a through which the terminal pins 69 are inserted. Notch 59b for passing through
is provided on a part of the outer periphery. Therefore, the terminal pin 69
For soldering, push open the left and right coil frames 54 and 55 as shown in FIG. 3, and the rotor 51 inside can be freely taken out and put in.

A jig hole 59c is further bored in the center of the terminal plate 59. As shown in FIG. 6, this hole 59c is used to insert a jig J through this jig hole 59c when press-fitting the interlocking arm 62 to the tip of the rotating shaft 53 of the rotor 51.
This is to easily determine the appropriate installation length.

Note that the outer circumferential diameter of this terminal plate 59 is larger than the inner circumferential diameter of the yoke 60. By doing so, the terminal board 59 also has the function of a conventional cover (cover 108 in FIG. 13), and also functions as a conventional mounting cover 107 as shown in FIG.
This, together with the elimination of the IIT, contributes to a compact IIT.

The yoke 60 is made of mild steel and has a thin cylindrical shape, covers the outer periphery of the coil frame 54, 55, and forms a magnetic field between it and the magnet 52 of the rotor 51 inside.

As mentioned above, the inner circumferential diameter of the yoke 60 is smaller than the outer diameter of the five terminal plates, and its lower end surface is in contact with the five terminal plates.

As shown in the unfolded state in FIG. 1, the insulator 80 consists of a substantially circular central connecting part 81 provided at the center and insulating pieces 82, 82 extending on both wings thereof.

A more detailed shape of the insulator 80 is shown in FIG.

A small hole 83 provided in the center of the central connecting portion 81 is a hole through which the rotating shaft 53 of the rotor 51 passes, and small holes 84. It is a .65 through hole.

As shown in FIG. 2, the central connecting portion 81 and the insulating pieces 8 on both wings
The joint 85.85 with 2 is narrowly tapered. This will be explained in detail later in the manufacturing method, but it is pushed by the yoke 60 and easily bent at these portions 85 and 85.

Further, in this insulator 80, the side of the insulating piece 82 facing the central connecting portion 81 forms a slope 86 with an angle θ. This also means that when pushed down by the yoke 60, the yoke 6
It is formed for the purpose of fitting smoothly without the tip of the 0 getting caught.

Next, a method for manufacturing the opening/closing blade drive device 50 will be described with reference to the above figures and FIGS. 7 to 12.

First, the entire manufacturing process will be explained based on FIG. 7.

First, a pair of terminal pins 69 are supplied to the flow of the coil frame 54 (55) and are press-fitted. (Step ①) 1 Next, a conductor for the coil is supplied and wound, and the end is connected to the terminal pin 69. (Step 2) In step 2, flux for soldering is applied to the terminal pin 69 to which the conductor is tied, and in step 2 the resistance of the coil 56 (57) is soldered. The rotor 5, which was made by press-fitting the rotating shaft 53 into the magnet 52, was checked (■).
1 is sandwiched between a pair of coil frames 54 and 55, and assembled (
Step ■), Apply the insulating tape material 90 of the insulator 80 above the set assembled in this way (■), then push in the yoke 60 and assemble it (■>), Connect the set assembled in this way to multiple terminals. Arrange them on the sheet 95 of the board 59 (■), put them in a soldering bath, and solder them.
, individual driving equipment! Separate and complete 50 pieces.

The insulator 80 supplied in step (2) is an insulating tape material 90 in which a large number of insulators 80 are arranged, as shown in FIG. Such an insulating tape material 90 is wound around a reel, for example, and is successively fed out.

In addition, the outer end of the insulating piece 82 of each insulator 80 and the tape material 9
It is connected to the side line portion 91 of 0 by a thin cut portion 87.

Note that the small holes drilled in the side line portion 91 are pitch holes 92 for feeding.

Further, the details of the step (2) in which the yoke 60 is lowered from above the insulating tape material 90, the insulator 80 is cut out and assembled into the yoke 60 are shown in FIGS. 9 and 10(a) to 10(a).
Shown in c).

As shown in FIG. 10(a), first, the rotating shaft 53 of the rotor 51
In step (2), you want to insert the yoke 60 into the small hole 83 of the central connecting part 81, lower the yoke 60 while aligning the center axis with the rotating shaft 83, press the lower end of the yoke 60 against the tape material 90, and gradually apply force. (Figure 10(b)).

Then, as the yoke 60 is pushed further, the first
As shown in Figure 0(c), the cut portion 87 of the insulating piece 82 is cut,
A single insulator 80 is inserted into the yoke 60 while covering the sides of the coils 56 and 57.

During the insertion operation, the slope 86 provided on the shoulder of each insulating piece 82
not only does not exert unnecessary resistance on the tip of the yoke 60, but also has the effect of gradually rounding the insulating piece 82 along the arcuate inner surface of the yoke 60 as it descends.

Next, step (2) will be explained in detail with reference to FIG.

In this step, the terminal board 59 is a terminal board sheet 95 formed by arranging a large number of terminal boards 59 as shown in the figure. Each terminal board 59 is provided with a cutting portion 95a so that it can be easily separated from each other.

The sets of drive devices 50 from the previous process are arranged on such a terminal board sheet 95, and soldered by immersing them in a solder tank H as shown in the figure.

Note that instead of the terminal board sheet 95, as shown in FIG. 12, a terminal board tape 97 that is elongated and can be wound onto a reel or the like may be used.

<Effects of Examples> According to the above embodiment, the following effects are achieved.

(1) Since no adhesive is required and tape-shaped insulators are used, insulation sheathing of coils, which was difficult to automate in the past, can now be done easily and quickly, reducing costs. This is a major contribution.

(2> By providing a central connecting part of the insulator, insulation from the coil opening/closing blade side is achieved, and the conventional mounting cover can be omitted and direct installation is possible, reducing the number of parts. Moreover, the mounting height can be lowered, contributing to miniaturization and cost reduction.

(3) The slope provided on the insulating piece makes it easy to assemble the yoke, contributing to automation.

(4) Since a translucent material is used for the insulator, it is possible to identify each coil after assembly, and no errors occur when assembling lead wires, etc.

(5) Since the terminal board is made flexible, it is now possible to open the coil frame and take in and take out the internal rotor even after assembly.

(6) Since the outer diameter of the terminal plate is made larger than the inner diameter of the yoke, there is no fear that the yoke will fall when removed, and the conventional cover can be omitted, greatly contributing to cost reduction and miniaturization.

(7) Since a large number of terminal boards are arranged and supplied in the form of sheets or tapes, it is possible to contribute to improved productivity.

[Effects of the Invention] The opening/closing vane drive device according to the present invention has the above-described configuration, and the insulation means between the side surface of the coil and the yoke is a flexible insulating material, and the end face of the coil frame on the opening/closing vane side Since the insulator is formed of a central connecting part that covers the coil and insulating pieces that cover the sides of the coil on both sides, it is possible to omit the conventional mounting cover and install it directly on the opening/closing blade side. The number of parts is reduced, and the mounting height can also be lowered, contributing to miniaturization and cost reduction. Furthermore, since a transparent material is used for the insulator, each coil can be identified after assembly, and no errors occur in assembling lead wires or the like.

In addition, in the manufacturing method, the insulator is formed into a long tape material without using an adhesive, and is easily separated from the tape material by pushing in the yoke, and can cover one end and side surface of the coil as it is. Because of this, it is possible to configure high-speed and efficient automation, which greatly contributes to cost reduction.

[Brief explanation of drawings]

1 to 6 show an embodiment of the drive device, and FIG. 1 shows an exploded view of the aperture blade device with the drive device attached. 3 is a perspective view, Fig. 2 is a plan view of the RrM insulator, Fig. 3 is an explanatory diagram of the action of the flexible terminal plate, and Fig. 4 is an explanatory diagram of the action of installing the drive device to the aperture blade mechanism. , Fig. 5(a) and Fig. 5(b) are explanatory diagrams of the installation of the magnetic detection element, Fig. 6 is an explanatory diagram of the operation of the terminal board, and Figs. 7 to 12 are explanatory diagrams of the manufacturing method. 7 is a process diagram, FIG. 8 is a plan view of the insulating tape material, FIGS. 9 and 10(a) to 10(b) are explanatory diagrams of the insulator assembly process, Fig. 11 is an explanatory diagram of the process of soldering the terminal board, Fig. 12 is a plan view of the terminal board tape, Fig. 13 is an exploded perspective view of a conventional drive device, and Fig. 13 is an exploded perspective view of a conventional drive device.
FIG. 4 is an explanatory diagram of the installation of a conventional magnetic detection element. S...Camera aperture device, 10...Aperture blade mechanism, 1
1, 12...Aperture blade (opening/closing blade), 20...Main plate, 2
1. Drive mounting part, 24. Shaft hole, 25. Screw, 26
・・Mounting hole, 27・・Positioning hole, 30・・Retainer plate, 5
0...Drive device, 51...Rotor, 52...Magnet, 53
・・Rotating shaft, 54・55・・Coil frame, 56・57・・
Coil, 58... Lead wire, 59... Terminal board, 60...
Yoke, 61...Lead wire (for magnetic detection element), 62...
- Interlocking arm, 69...Terminal bin, 70...Magnetic detection element, 80...Insulator, 81...Central connecting part, 82...Insulating piece, 85...Connecting part, 86...Slope, θ... Inclination angle of slope, 87. Cutting portion, 90. Insulating tape material, 91.
- Tape side line part, 92... Pitch hole, 95... Terminal board sheet, H... Solder bath, 97... Terminal board tape. Figure 1, /1 Taku-〇

Claims (3)

[Claims] (1) A rotor equipped with a rotating shaft that transmits driving force to the opening/closing blades, a pair of coil frames that sandwich this rotor, coils wound around these coil frames, and these coils protected by insulating means, In the opening/closing blade drive device comprising a yoke into which the pair of coil frames are fitted inside, the insulating means is a flexible insulating material and includes a central connecting portion that covers the opening/closing blade side end surface of the coil frame. An opening/closing vane driving device comprising: an insulating piece formed on both sides of the central connecting portion to cover at least both sides of the coil; (2) The opening/closing blade drive device according to claim 1, wherein the insulator is made of a translucent material. (3) A flexible insulating tape material is constructed in which a large number of insulators are arranged adjacent to each other, each consisting of a central connecting part and insulating pieces that cover at least both sides of the coil on both sides of the central connecting part. The coil frames are arranged so that they can be drawn out according to the assembly tact, and the process of supplying the coil frames and winding the coils is performed, as well as the process of supplying the coil frames and winding the coils. and a step of extrapolating a cylindrical yoke constituting a magnetic path onto the outer periphery of the coil frame housing the rotor therein. During this yoke extrapolation step, , the insulating tape material is overlapped at a predetermined position on the coil frame, and then the yoke is pressed against the insulating tape material from the rotating shaft side, and the insulator is separated from the insulating tape material by the pressing force of the yoke. A method for manufacturing an opening/closing vane drive device, characterized in that the central connecting part covers one end surface of the coil frame and the insulating piece covers the side surface of the coil along the inner periphery of the yoke after being separated.