JPH1032131A - Core for cylindrical coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the core for cylindrical coil with which the yield of production of core material can be improved, while the filling efficiency of the core inside a cylindrical member, where the coil is wound around, is enhanced. SOLUTION: The first core 1 and the second core 2 are inserted into a cylindrical body 3, when a coil is wound. The first core 1 has almost a square-shaped cross section, and its four corner parts 1a are in contact with the inner circumference of the cylindrical body 3. Also, the second core 2 has a rectangular cross-section, its one side is closely fixed to the side face of the first core 1, and its two outside corner parts 2a are in contact with the main circumference of the cylindrical body 3. With such a structure, the filling efficiency of the core on the inside of the cylindrical body 3 can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron core for a cylindrical coil.

[0002]

2. Description of the Related Art There are various types of transformers using electromagnetic induction, one of which is provided in an ignition device of an automobile engine. In this ignition device, as shown in FIG.
02 is connected to the primary coil 102a of the
The second secondary coil 102b is connected to each ignition plug 104 via a distributor 103. Further, a capacitor 105 and a breaker contact 106 are connected in parallel, and these are connected between the primary coil 102a and the secondary coil 102b.

In this igniter, a breaker contact 106 is opened to allow a current to flow from the battery 101 to the primary coil 102a of the transformer 102.
02 is the secondary coil 102b.
When it is connected to the ignition plug 104 through the opening, the breaker contact 106 is opened and the primary coils 102a and 102
By the mutual induction action of the secondary coil 102b, a high voltage is generated in the secondary coil 102b, and this high voltage is applied to the ignition plug 104 via the distributor 103, and a spark is generated in the ignition plug 104.

As shown in FIG. 7, a transformer 102 has an iron core 112 inserted into a cylindrical body 111, and a primary coil 102a and a secondary coil 102b are wound around the cylindrical body 111. The iron core 112 is formed by laminating strip-shaped directional electromagnetic steel sheets, and has a substantially square cross section.

[0005] The transformer 102 has no particular limitation on its size, and therefore has a simple structure.
There is no special contrivance on the shape of the iron core 112.

In recent years, a distributor 103 and a distributor 103 in an ignition device have been used.
Attempts have been made to omit the respective high-voltage cords that connect the ignition plugs 104 with each other. This is distributor 1
This is because it is desirable to eliminate the distributor 103 and each high-voltage cord in order to increase the failure occurrence rate of the power supply unit 03 and to reduce the cost.

Specifically, each transformer is directly attached to each spark plug, the voltage of the battery is boosted by these transformers, a high voltage is applied to each spark plug, and a spark is generated in these spark plugs. Let it.

Since these transformers are directly attached to each spark plug, miniaturization is required. In particular, the outer diameter of the transformer must be reduced until it is substantially the same as the spark plug.

However, if the outer diameter of the transformer is reduced while the cross section of the iron core of the transformer remains square,
The capacity of the iron core becomes insufficient, and the magnetic resistance of this transformer increases. To cope with this, the sectional shape of the iron core 121 is changed as shown in FIGS.
There is no alternative but to increase the filling efficiency of the iron core 121 inside the inside.

[0010]

However, when the iron core 121 shown in FIG. 8 is manufactured by the conventional method, there is a problem that the yield of the material is deteriorated.

[0011] This conventional construction method means that each divided range 123a of a strip-shaped grain-oriented electrical steel sheet 123 as shown in FIG.
The guide holes 124 and the concave and convex portions 125 for press-fitting are formed in advance, and the strip-shaped directional electromagnetic steel sheet 123 is indicated by an arrow x.
Are moved intermittently in the direction shown by the arrow, and each divided range 123a of this strip-shaped grain-oriented electrical steel sheet 123
It is sequentially conveyed to the second stage B0 and the third stage C0, and each divided range 123a is processed for each of these stages.

In the first stage A0, the divided range 123a
Are punched out with a punch. The distance between these rectangular regions 126 is
This corresponds to the width of each strip-shaped steel plate 121-1 in the iron core 121 in FIG.

In the second stage B0, the divided range 1
Two rectangular areas 127 indicated by dotted lines in 23a are punched out by a punch. The distance between these rectangular regions 127 corresponds to the width of each strip-shaped steel plate 12-2 in the iron core 121 in FIG.

Further, in the third stage C0, a rectangular area 128 indicated by a dotted line in the divided range 123a is punched out by a punch. The width of the rectangular region 128 corresponds to the width of each strip-shaped steel plate 12-3 in the iron core 121 in FIG.

In order to manufacture the iron core 121, each rectangular area 126 is punched out in the first stage A0, then passes through the second stage B0, and passes through the third stage C0.
8 to thereby cut out the strip-shaped steel plate 1 of the iron core 121.
21-1 is formed. In the third stage C0, as the strip-shaped steel plate 121-1 is formed, the strip-shaped steel plate 121-1 is pressed. When the formation and pressing of the strip-shaped steel plate 121-1 are repeated three times, the three strip-shaped steel plates 121-1 are stacked, and the concave and convex portions 125 of the strip-shaped steel plate 121-1 are fitted to each other. These strip-shaped steel plates 121-1 are mutually locked and integrated.

Subsequently, after passing through the first stage A0 and punching out each rectangular area 127 in the second stage B0, the rectangular area 128 is punched out in the third stage C0.
A strip-shaped steel plate 121-2 of the iron core 121 is formed and pressed.
The formation and pressing of the strip-shaped steel plates 121-2 are repeated four times, and the four strip-shaped steel plates 121-2 are connected to the respective strip-shaped steel plates 12-2.
1-1, each of the uneven portions 125 of these strip-shaped steel plates.
Are fitted to each other to integrate them.

Further, the rectangular area 128 is punched out at the third stage C0 by passing through the first and second stages A0 and B0, and a strip-shaped steel plate 121-3 of the iron core 121 is formed and pressed. The formation and pressing of the strip-shaped steel plate 121-3 are repeated 17 times, and the 17 strip-shaped steel plates 121-3 are laminated on the respective strip-shaped steel plates 121-1 and 12-2, and these are integrated. .

Thereafter, similarly, four strip-shaped steel plates 121-2,
Then, the three strip-shaped steel plates 121-1 are sequentially punched out and laminated, and when these strip-shaped steel plates are integrated, the iron core 121 is completed.

That is, three strip-shaped steel plates 121-1 and 121-1, 4
Strip steel plates 121-2, 17 strip steel plates 121-
The iron core 121 is obtained by sequentially laminating three and four strip-shaped steel plates 121-2 and three strip-shaped steel plates 121-1 and a total of 31 strip-shaped steel plates.

On the other hand, the length of each strip-shaped steel sheet is 70 mm, the width of the strip-shaped directional electromagnetic steel sheet 123 is 14.6 mm, the width of the strip-shaped steel sheet 121-1 is 5.0 mm, and the width of the strip-shaped steel sheet 121-2. 7.6 mm, the width of the strip-shaped steel plate 121-3 is 9.4 mm
And The thickness of the strip-shaped directional electromagnetic steel sheet 123 is 0.3 mm, and the thickness of the iron core 121 is 9.3 m.
m. As a result, the inner diameter of the iron core 121 is 10.8 m.
m, and the shape just fits in the cylindrical body 122.

The length of the divided area 123a is 80 mm.
And Further, with respect to a total of 31 strip-shaped steel plates serving as the iron cores 121, the respective iron cores 12 are separated to separate the iron cores 121.
One strip-shaped steel sheet sandwiched between the spacers is formed.

Under these conditions, the ratio of the portion serving as the iron core 121 of the strip-shaped grain-oriented electrical steel sheet 123, that is, the yield of the material, is very bad at 48.4%.

The first, second and third stages A0,
Since B0 and C0 are connected, a press device for raising and lowering the punches of these stages becomes large, and there is a disadvantage that capital investment is increased.

Accordingly, an object of the present invention is to provide a cylindrical coil capable of improving the yield rate of the material of the iron core while increasing the filling efficiency of the iron core inside the cylindrical body around which the coil is wound. To provide an iron core.

[0025]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to an iron core for a cylindrical coil inserted inside a cylindrical body around which a coil is wound, the iron core having a quadrangular prism shape. A first iron core substantially in contact with the inner periphery of the cylindrical body at four corners of the prism, and a quadrangular prism shape, which is inserted into each gap between the first iron core and the inner periphery of the cylindrical body. Side is first
A plurality of second iron cores that are in close contact with the iron core and that are substantially in contact with the inner periphery of the cylindrical body at two corners of the quadrangular prism, wherein the first iron core and each of the second iron cores are Strip-shaped magnetic plates of substantially the same length are laminated, and these magnetic plates are mutually locked.

According to such a configuration, the first iron core and each of the second iron cores are separately formed, then inserted into the inside of the cylindrical body and come into close contact with each other, and are integrally formed together with the cylindrical body. Be transformed into Since the first and second iron cores are each a quadratic prism, they are formed by laminating strip-shaped magnetic plates of the same width.

Here, for the first iron core and the second iron core, a strip-shaped magnetic plate of an appropriate width as a material is separately prepared, and a strip-shaped magnetic plate is provided for each of these strip-shaped magnetic plates. If the iron core is manufactured by punching out the body plate and forming and laminating each of the strip-shaped magnetic plates, the yield of the material can be improved.

[0028]

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

FIG. 1 shows an embodiment of an iron core for a cylindrical coil according to the present invention. In the figure, a first iron core 1 and each second iron core 2 are inserted inside a cylindrical body 3 around which a coil (not shown) is wound. The first iron core 1 has a substantially square cross section, and is in contact with the inner periphery of the cylindrical body 3 at four corners 1a. Further, each of the second iron cores 2 has a rectangular cross-sectional shape, one side surface of which is in close contact with the side surface of the first iron core 1 and the inner peripheral surface of the cylindrical body 3 at two outer corner portions 2a. ing.

The iron core of this embodiment has a high filling efficiency of the iron core inside the cylindrical body 3 as in FIG. For this reason, the iron core of this embodiment is suitable as the iron core of the transformer directly attached to each spark plug of the automobile engine described above.

The first iron core 1 and each of the second iron cores 2 are separately formed. 1st iron core 1 and each 2nd
After the iron core 2 is inserted into the cylindrical body 3, an adhesive is poured into the cylindrical body 3 to integrate the iron cores 1, 2 and the cylindrical body 3. Alternatively, the iron cores 1 and 2 and the cylindrical body 3 may be integrated by pressing each other without using an adhesive. Furthermore, these iron cores 1 and 2 and the cylindrical body 3 may be integrated by screws, metal fittings, or the like.

Such a first iron core 1 and each second iron core 2 are
Each of them is formed separately, and is formed separately from each strip-shaped grain-oriented electrical steel sheet of each width. For example, the first iron core 1 is formed from a band-shaped directional electromagnetic steel sheet 4 as shown in FIG. 2, and the second iron core 2 is formed from a band-shaped directional electromagnetic steel sheet 5 as shown in FIG.

That is, the strip-shaped grain-oriented electrical steel sheet 4 shown in FIG.
Are divided into respective divided ranges 4a, and guide holes 6 are formed in advance in these divided ranges 4a, and the strip-shaped grain-oriented electromagnetic steel sheet 4 is intermittently moved in a direction indicated by an arrow x, Each divided area 4a is sequentially conveyed to a first stage A1 and a second stage B1.

In the first stage A1, every time the divided area 4a of the strip-shaped grain-oriented electrical steel sheet 4 is conveyed, three concave and convex portions 8 are formed in the divided area 4a by a punch 7 of a press device as shown in FIG. To form

In the subsequent second stage B1, as shown in FIG.
1 and the strip-shaped steel plate 11 is
The user pushes down from a to the inside of the holding ring 13.

The first and second stages A1, B1 as described above
Is repeated, the plurality of strip-shaped steel plates 11
3 and each time the punch 9 reaches the bottom dead center, the concave and convex portions 8 of these strip-shaped steel plates 11 are fitted with each other, and these strip-shaped steel plates 11 are mutually locked. And unite.

When a predetermined number of strip-shaped steel plates 11 are stacked and locked, the first iron core 1 is formed. One of the first
When the iron core 1 is formed, in the first stage A _1, is pushed up punch 7 until range punch 7a, the portion of the uneven portion 8 of one division area 4a by the punch 7a are vent dropped, subsequently In the second stage B1, the strip-shaped steel plate 14 is punched from the divided area 4a. This strip-shaped steel plate 14 does not have each of the concavo-convex portions 8 because the portions of each concavo-convex portion 8 have been removed in the first stage A1, and therefore the first iron core 1 and the next one are formed. Other first iron core 1
Does not lock. This strip-shaped steel plate 14 is used for each first iron core 1.
It is sandwiched between them and serves as a spacer that prevents the iron cores 1 from locking each other.

The first iron core 1 thus formed is dropped on the pedestal 10 and taken out from the pedestal 10.

Similarly, each grain-oriented electrical steel sheet 5 shown in FIG. 3 is divided into each divided area 5a, and each guide hole 15 is formed in each of these divided areas 5a. Is sequentially and intermittently conveyed to a first stage A2 and a second stage B2.

In the first stage A 2, each of the divided areas 5 of the strip-shaped grain-oriented electrical steel sheet 5 is moved by a punch (not shown).
a, three concave and convex portions 16 are sequentially formed. In the second stage B2, each strip-shaped steel plate 17 is punched out from each divided range 5a by a punch (not shown) and pressed.

When these stages A2 and B2 are repeated, these strip-shaped steel plates 17 are stacked and locked. When a predetermined number of strip-shaped steel plates 17 are stacked, one second iron core 2 is formed.
The portion of each of the concave and convex portions 8 of the two divided ranges 5a is the first stage A
2 and in the second stage B2,
A strip-shaped steel plate as a spacer is punched from a, and the spacer is laminated on the second iron core 2. This second iron core 2
Is dropped on a cradle and taken out from here.

Here, the inner diameter of the cylindrical body 3 is 10.8 mm,
The length of the cylindrical body 3 is set to 70 mm. The thickness of each of the strip-shaped directional electromagnetic steel plates 4 and 5 is 0.3 mm.

In this case, a strip-shaped steel sheet 7.6 mm × 70 mm is punched from the strip-shaped grain-oriented electrical steel sheet 4, and 25 strip-shaped steel sheets 11 are laminated to form a 7.5 mm-thick first iron core 1. To form Also, a strip-shaped grain-oriented electrical steel sheet 5
A 5.0 mm × 70 mm strip-shaped steel plate 17 is punched out from the above, three strip-shaped steel plates 17 are laminated, and the thickness is 0.9 m.
m second iron cores 2 are formed.

When the first iron core 1 and the four second iron cores 2 are combined as shown in FIG. 1, these iron cores 1 and 2 just fit inside the cylindrical body 3.

Now, the width of the strip-shaped directional electromagnetic steel sheet 4 for punching the strip-shaped steel sheet 11 is 10.6 mm, the length of the divided area 4a is 80 mm, and one strip serving as a spacer is provided for each of the 25 strip-shaped steel sheets 11. The shaped steel plate 17 is punched.
Further, the width of the strip-shaped directional electromagnetic steel sheet 5 for punching the strip-shaped steel sheet 17 is 8.0 mm, the length of the divided range 5a is 80 mm,
For each of the three strip-shaped steel plates 17, one strip-shaped steel plate serving as a spacer is punched.

Under these conditions, the ratio of the portions that become the first and second iron cores 1 and 2 of the strip-shaped grain-oriented electrical steel sheets 4 and 5, that is, the material yield is 60.6%. It is.
Therefore, compared with the case of the conventional iron core 121 described above, the yield of the material is sufficiently improved.

Further, in each of the first iron core 1 and the second iron core 2, only one punch and one punch are moved up and down, so that it is not necessary to increase the size of the press device, and it is possible to reduce capital investment. Can be.

FIG. 5 shows another embodiment of the iron core for a cylindrical coil of the present invention. Here, in addition to the first and second iron cores 1 and 2, four third iron cores 21 are inserted into the inside of the cylindrical body 3 to further enhance the filling efficiency of the iron core inside the cylindrical body 3. I have.

Also in this case, the third iron core 21 is formed by stamping and laminating each strip-shaped steel sheet from a strip-shaped directional electromagnetic steel sheet.
If the band-shaped grain-oriented electrical steel sheet is made close to the width of the strip-shaped steel sheet, the yield of the material does not decrease at all.

The present invention is not limited to the above embodiments, and various modifications are possible. For example,
A fourth iron core may be provided in close contact with the side surface of each third iron core. Also, the cross-sectional shape of the first iron core should not be square,
The shape may be rectangular, and the combination of the first iron core and each of the second iron cores can be variously changed.

[0051]

As described above, the iron core for a cylindrical coil of the present invention is obtained by inserting the first iron core and the second iron core into a cylindrical body and integrating them. The first and second iron cores are separately formed, and are formed by laminating strip-shaped magnetic plates. Therefore, for the first iron core and the second iron core, if a strip-shaped magnetic plate having an appropriate width as a material is separately prepared, the yield of the material can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of an iron core for a cylindrical coil of the present invention.

FIG. 2 is a view showing a process for forming a first iron core of FIG. 1;

FIG. 3 is a view showing a process for forming a second iron core of FIG. 1;

FIG. 4 is a diagram schematically showing a pressing device for forming the first iron core of FIG. 1;

FIG. 5 is a plan view showing another embodiment of the iron core for a cylindrical coil of the present invention.

FIG. 6 is a diagram schematically showing an ignition device of an automobile engine.

FIG. 7 is a plan view showing an iron core of a transformer in the apparatus of FIG. 6;

FIG. 8 is a plan view showing another conventional iron core.

FIG. 9 is a perspective view showing the iron core of FIG. 8;

FIG. 10 is a view for explaining a conventional process for manufacturing an iron core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st iron core 2 2nd iron core 3 Cylindrical body 4, 5 Strip-shaped directional electromagnetic steel plate 6, 15 Guide hole 7 Punch 8, 16 Uneven part 9 Punch 10 Receiving stand 11, 14, 17 Strip-shaped steel plate 12 Die 13 Retaining ring 21 Third iron core

Claims (2)

[Claims] 1. An iron core for a cylindrical coil inserted inside a cylindrical body around which a coil is wound, wherein the iron core has a quadrangular prism shape, and is substantially in contact with the inner periphery of the cylindrical body at four corners of the quadrangular prism. A first iron core and a quadrangular prism, which are inserted into respective gaps between the first iron core and the inner periphery of the cylindrical body, and the side surfaces of the quadratic prism are in close contact with the first iron core; A plurality of second iron cores substantially in contact with the inner periphery of the cylindrical body at two corners, wherein the first iron core and each of the second iron cores are strip-shaped magnetic bodies having substantially the same length as the cylindrical body. An iron core for a cylindrical coil formed by laminating plates and interlocking these magnetic plates. 2. A quadrangular prism, which is inserted into each gap between each second iron core and the inner periphery of the cylindrical body, and the side surface of the quadratic prism is in close contact with each second iron core, and A plurality of third iron cores substantially in contact with the inner periphery of the cylindrical body at two corners are further provided. Each of the third iron cores is formed by laminating strip-shaped magnetic plates having substantially the same length as the cylindrical body. 2. The iron core for a cylindrical coil according to claim 1, wherein said magnetic plates are mutually locked.