JPH09167712A - Ignition coil magnetic core manufacturing jig and manufacturing method of magnetic core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity, quality reliability and safety by winding an amorphous alloy foil as a magnetic core uniformly and fast from the winding start to the winding end. SOLUTION: The end portion of an amorphous alloy foil 51 supplied from a foil supply unit is put between a pair of core halves 3. The core halves 3 are rotated integrally with each other to wind the amorphous alloy foil 51. After completing the winding, the amorphous alloy 51 is cut from the foil supply unit and the paired core halves 3 are drawn from both ends of the amorphous alloy 51 to the outside. It is possible to prevent irregular winding due to a bounce at the time the winding begins, the foil 51 from becoming a larger dimension and the end portion from hitting an operator on the fingers, arms or the like to injure the operator. In this case, the tip end portion of each of the core halves 3 is fitted into and aligned with a fitting hole 6 of an alignment member 5, thereby making it easy to put the amorphous alloy foil 51 between the paired core halves 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for producing a magnetic core of an ignition coil for an independent ignition system used in an internal combustion engine and a magnetic core producing method.

[0002]

2. Description of the Related Art As shown in FIG. 7, an ignition coil of this type includes a magnetic core 41 as a magnetic body, a primary winding bed 42 mounted on the magnetic core 41, and a primary winding side of the primary winding bed 42. A primary coil 43 formed by winding an enameled wire as a winding wire, a secondary winding floor 44 fitted to the outside of the primary winding floor 42 on which the primary coil 43 is formed, and the secondary winding. An ignition coil main body 46 is formed by a secondary coil 45 formed by winding an enameled wire as a secondary winding on the floor 44, and the ignition coil main body 46 is housed in a case 47. Has been done.

Here, the magnetic core 41 generally has a thickness of 0.
There are a method of punching a 35-0.5 mm electromagnetic rope plate by a die and then laminating it, and a method of winding the electromagnetic rope plate around the axis as many times as a roll. there were.

[0004]

By the way, since these independent ignition type ignition coils are mounted so as to project from the upper surface of the internal combustion engine, they are installed between parts such as the duct of the inlet manifold laid out on the upper surface side of the internal combustion engine. There were constant problems with the installation space. Therefore, recently, as a countermeasure, there is an attempt to install the entire ignition coil in the plug hole. In this case, two methods are conceivable: a method of enlarging the diameter of the plug hole and inserting the ignition coil into the internal combustion engine, and a method of reducing the diameter of the ignition coil without changing the diameter of the plug hole.

First of all, if the ignition coil is inserted into the internal combustion engine by enlarging the diameter of the plug hole, for example, when using a narrow valve such as a 4-valve system, the mounting angle of the valve around the plug hole is set. I have to change it. Then, characteristics such as fuel consumption and horsepower are deteriorated, which is inconvenient.

Therefore, as a technique for reducing the diameter of the ignition coil, as shown in FIG. 8, regarding the magnetic core 41, an amorphous alloy foil 51 such as Fe-Si-B system having a higher relative magnetic permeability than the electromagnetic steel plate is used. Proposed examples have been proposed in which the material is supplied from a predetermined supply roller, and the material is formed in a roll-tight winding around a small-diameter mandrel 52 as a jig as many times as necessary.
As described above, when the above-mentioned amorphous alloy foil is used as the magnetic core 41, since the relative magnetic permeability is high, the disconnection of the magnetic core required to obtain the inductance equivalent to that of the magnetic core made of the conventional electromagnetic steel plate. The area can be reduced, the magnetic core 41 can be made compact, and the diameter of the entire ignition coil can be made small.

By the way, in the above proposed example, since the amorphous alloy foil 51 having a high hardness is to be wound around the winding core 52 in a small diameter, the elastic restoring force acts strongly at the beginning of winding, and the end of the amorphous alloy foil 51. The part (edge) repels and the work becomes difficult. In particular, since the end of the amorphous alloy foil 51 is still sharp unless it is polished even after cutting, if this work is performed manually, the end may hit a finger or an arm, possibly causing injury.

Further, the amorphous alloy foil 51 is supplied from a supply roller and is formed into a tightly packed shape around the winding core 52, and then the amorphous alloy foil 5 is already wound as the magnetic core 41.
1 and the amorphous alloy foil on the supply roller side were separated from each other. Therefore, when the amorphous alloy foil 51 is cut, the amorphous alloy foil on the supply roller side is rewound on the supply roller by the elastic restoring force. Then, in the next winding operation, it is necessary to grip the end portion of the amorphous alloy foil from the supply roller and pull it out again. Therefore, there has been a long-awaited demand for a method of reducing such trouble.

In view of the above-mentioned problems, the present invention provides a method for starting and ending winding of an amorphous alloy foil as a magnetic core.
To provide a jig for producing a magnetic core of an ignition coil and a method for producing a magnetic core, which can be uniformly and quickly carried out to improve productivity and quality stability, and improve safety. To aim.

[0010]

According to a first aspect of the present invention, there is provided a magnetic core forming jig for winding a metal foil made of a magnetic material to form a magnetic core of an ignition coil. , A pair of core half members that form a core for winding the metal foil in pairs, and the metal foil is provided between the core half members and the other core half members. Is formed with a holding surface for holding the end portion of the.

Specifically, as described in claim 2, each of the winding core half members is formed in a shape in which a substantially columnar rod member is obliquely divided from one end portion to almost the other end portion, and each winding member is wound. The split surface of the core half member is the sandwiching surface.

Preferably, as described in claim 3, a positioning member for positioning the leading end portions of the other core half members is fixed to the base end portions of the respective core half members.

As a method of forming a magnetic core in which the metal foil is wound by using the magnetic core forming jig, as described in claim 4, (a) an end portion of the metal foil supplied from the foil supply side. A step of sandwiching both core half members with a sandwiching surface, (b) a step of integrally rotating both core half members around a central axis, and winding the metal foil, (c) After the completion of winding the metal foil, a step of cutting the metal foil from the foil supply side, and (d) after the completion of winding the metal foil, both core half members from both ends of the metal foil toward the outside. And a step of pulling out each.

Here, in the step (a),
As described above, by positioning the leading end portions of the respective core half members by the positioning members fixed to the other core half members, the end portions of the metal foil supplied from the foil supply side can be positioned at the both cores. The end portions of the metal foils can be easily pressed by the pressing surfaces of the two core half members while being brought into contact with the holding surfaces of the half members.

Preferably, at least in the step (c), the cut end of the metal foil wound around the winding core half member is axially supported by a predetermined pressing member as described in claim 6. Hold in the direction of your heart.

More preferably, at least after the step (c), as described in claim 7, the cut end of the metal foil cut on the foil supply side is placed on the jig for magnetic core production. Hold it in place and fix it with a predetermined holding member.

More preferably, in the step (b), as described in claim 8, the tension of the metal foil is detected by a predetermined tension detecting means, and based on the detection result by the tension detecting means. At least one of the supply speed on the foil supply side and the rotation speed of the magnetic core producing jig is adjusted by a predetermined tension adjusting means.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In one embodiment of the present invention, an amorphous alloy foil 51 such as Fe—Si—B having a thickness of 0.025 mm is wound to form a magnetic core having a diameter of about 10 mm. (See FIG. 8) At this time, an end (edge) of the amorphous alloy foil is sandwiched between a pair of winding tools having a shape in which a small-diameter metal rod is obliquely cut, and is fastened to the amorphous alloy foil. While applying tension, the jig is rotated to form the amorphous alloy foil in a roll-like shape.

<Structure of Magnetic Core Making Jig> FIG. 1 is a view showing a magnetic core making jig A1 of this embodiment. The diameter of the magnetic core producing jig A1 is actually set to be smaller than the length shown in the figure, but is drawn thicker than it actually is for easier understanding. This magnetic core making jig A1
1 comprises a first winding tool 1 and a second winding tool 2 as shown in FIG. 1. Each of the winding tools 1 and 2 has a substantially wedge-shaped winding core half member 3,
A positioning member 5 is provided which is fixed to the base end of each winding core half member 3 and positions the winding tools 1 and 2 relative to each other.

The winding core half member 3 is, for example, one substantially cylindrical metal rod having a small diameter of about 3.5 mm, and is formed into a substantially wedge shape obliquely divided from one end to the other end. Is formed, and the dividing surface 4 of this winding core half member 3 is
It is formed flat and smooth, and functions as a holding surface for holding and holding the end portion of the amorphous alloy foil 51.

The positioning member 5 is a rectangular member having a diameter larger than that of each core half member 3, and is fixed to the base end portion of the divided cross section 4 of each core half member 3 by integral molding or a fixing means such as a pin. The positioning member 5 of each of the winding tools 1 and 2 is formed with a fitting hole 6 into which the tip of the winding core half member 3 of the other winding tool 1 or 2 is fitted. The hole wall surface of the fitting hole 6 is
The other core half member 3 has a shape in which the tip end portion of the core half member 3 is closely fitted in the axial direction, and one surface of the hole half wall also serves as a part of the dividing surface 4 of each core half member 3, so that both cores Half member 3
The respective divided sections 4 can be closely contacted with each other, so that the amorphous alloy foil 51 can be held between the divided sections 4.

<Structure of Magnetic Core Producing Device> The magnetic core producing jig A1 is used by the magnetic core producing device A2 shown in FIGS. 2 and 3. The magnetic core producing apparatus A2 is composed of a foil winder 11 in which the above-mentioned magnetic core producing jig A1 is installed, and a foil feeder 12 for supplying the amorphous alloy foil 51 to the foil winder 11. It

The foil winding machine 11 is generally used in the field of wire winding and the like. Specifically, the support chuck 13 that holds the base end of the magnetic core producing jig A1 is used.
Is rotatably supported on the support base 14, and by the slide bearing mechanism 15, the support base 14 is orthogonal to the winding direction of the main body 20 of the foil supply machine, which will be described later. Direction), and the motor and shaft (not shown) that are arranged on the support base 14
The support chuck 13 is rotated by a rotating device 16 including a power transmission member such as the above. In addition, a line speed take-up edge control device (EPC) 17 (first device) including an electric actuator equipped with a spring or the like (first
The tension of the amorphous alloy foil 51 is adjusted between the shaft (not shown) of the rotating device 16 and the support chuck 13 by the tension adjusting means (1). Further, a pinch roller 18 (pressing member) for pressing the amorphous alloy foil 51 wound around the magnetic core forming jig A1 is arranged above the installation position of the magnetic core forming jig A1.

The foil feeder 12 is composed of the foil feeder main body 20.
A support member 22 for rotatably supporting the material supply roller 21 of the amorphous alloy foil on the main body 20 of the foil feeder, a rotation device 23 for rotating the support member 22, and a portion between the support member 22 and the foil winder 11. First to fourth relay rollers 24a for relay-transporting the amorphous alloy foil 51 in the relay region of
24d, a tension sensor 25 (tension detecting means) for detecting the tension of the amorphous alloy foil 51 in the relay region between the support member 22 and the foil winder 11, and support based on the detection result of the tension sensor 25. A tension adjusting brake 26 (second tension adjusting means) for limiting the rotation of the member 22 and adjusting the tension of the amorphous alloy foil 51.
And the amorphous alloy foil 51 in the fourth relay roller 24d arranged closest to the foil winder 11.
The pinch roller 28 (pressing member) that presses down the amorphous alloy foil 51 near the pinch roller 28.
The rotary encoder 29 is provided for measuring the supply amount (length) of.

These foil winding machine 11 and foil supply machine 12
Each unit of is controlled by a predetermined control unit 30. FIG.
Is a block diagram showing the control unit 30. A general computer having a CPU, a ROM, a RAM and the like is used as the control unit 30, and all the arithmetic operations are executed by pre-stored software. The rotating device on the foil winding machine 11 side is used. 16 and foil feeder 1
A rotation control means 31 for synchronously rotating the rotating device 23 on the second side at a predetermined speed, and a tension control means 32 for controlling the line speed winding edge control device 17 and the tension adjusting brake 26 based on the detection result of the tension sensor 25. And a switching means 33 for switching the tension mode of the amorphous alloy foil 51 and the detection range of the tension sensor 25 accordingly to two systems.

Here, the rotation speed (line speed) of the rotation control means 31 is variable in consideration of winding up as a bench test. Specifically, the core A is a jig for magnetic core production A.
3.5π (mm / revolution) for 1 diameter, 10π for finishing diameter
(Mm / rotation). As described above, since the winding thickness is small, the line speed can be set at a maximum value of 10π (mm / revolution).

Further, the rotation control means 31 has a function of stopping after the rotary encoder 29 detects that the amorphous alloy foil 51 having a constant length is supplied, and specifically, the foil winding is performed. The rotation of the rotating devices 16 and 23 is set to stop when the winding amount of the amorphous alloy foil 51 in the take-up machine 11 reaches 5512 mm. The grounds for calculating the winding amount as the stop condition here are as follows. First, the diameter of jig A1 is 3.5 m
m, and the desirable diameter after winding the magnetic core 41 is 1
Since it is 0 mm and the thickness of the amorphous alloy foil 51 is 0.025 mm, the number of windings in the foil winder 11 is (10-3.5) /0.025=260 rotations. Here, since the simple average outer circumference of the amorphous alloy foil 51 wound as the magnetic core 41 is (3.5π + 10π) /2=21.2 mm, the estimated winding amount is 21.2 × 260 = 5512 mm. It can be seen that it is. Therefore, the winding amount is 5512
If it is set to mm, the winding diameter of the amorphous alloy foil 51 can be set to 10 mm.

Since the switching means 33 requires a higher tension at the beginning of winding than at the end of winding, the switching means 33 is divided into the first half and the second half of the time zone depending on the elapsed time after the beginning of winding, and the first half is 0 to 10 kg. This is because the tension of the amorphous alloy foil 51 is detected in a high detection range, and the tension of the amorphous alloy foil 51 is detected in a detection range as low as 0 to 5 kg since the relatively weak tension is sufficient in the latter half. For this purpose, the switching means 33 moves the second relay roller 24b arranged in the vicinity of the tension sensor 25 up and down by an elevating device (not shown) to switch between the strong tension mode (up position) and the weak tension mode (down position). And a detection range switching function for switching the detection range of the tension sensor 25 in accordance with this switching.

In each tension mode switched by the switching means 33, the tension control means 32 judges whether the tension of the amorphous alloy foil 51 detected by the tension sensor 25 is an appropriate tension, and the tension is If too strong, line speed take-up edge control device 17
Has a function of slightly slowing the rotation speed of the rotating device 16 by a predetermined time, and conversely, when the tension is too weak, has a function of slightly slowing the rotation speed of the rotating device 23 by a predetermined time by the tension adjusting brake 26. . When the tension of the amorphous alloy foil 51 is significantly different from the predetermined value and an abnormality is likely to occur, a tension abnormality alarm is also output. Further, an alarm of material shortage may be output.

<Operation> In the above structure, at the beginning of winding the magnetic core producing jig A1, the winding tools 1 and 2 are manually operated.
While bringing the end portion of the amorphous alloy foil 51 into contact with the split surface 4 of the core half member 3, the front end of each core half member 3 is fitted into the positioning member 5 of the other winding tool 1, 2. 6, and the divided cross section 4 of the two core half members 3 is pressed against the end portion of the amorphous alloy foil 51 as shown in FIG. Then, the winding tools 1 and 2 are rotated around the central axis to start winding the amorphous alloy foil 51. At this time, in order to improve the winding accuracy of the amorphous alloy foil 51, the second relay roller 24b is raised to the strong tension mode in the first half including the winding start, and the detection range of the tension sensor 25 is set to 0 to 10 kg span. The tension control means 32 adjusts the tension to tightly roll the magnetic core forming jig A1. When the rotary encoder 29 supplies a certain amount of the amorphous alloy foil 51, the switching means 3
The second relay roller 24b is lowered by 3 and the detection range of the tension sensor 25 is switched to a span of 0 to 5 kg, and the tension control means 32 adjusts the tension to tightly wind the magnetic core forming jig A1. To do.

When the rotary encoder 29 detects that the supply amount from the material supply roller 21 is 5512 mm, the winding diameter of the magnetic core producing jig A1 is 10 mm as described above. Therefore, the rotation control means 31 automatically stops the rotation of the winding tools 1 and 2 by the rotation device 16 and the rotation of the material supply roller 21 by the rotation device 23 at this point. At this time, the pinch roller 18 descends toward the magnetic core producing jig A1, and the produced amorphous alloy foil 51 on the magnetic core 41 is pressed by the pinch roller 18. Further, the pinch roller 28 also descends on the fourth relay roller 24d between the material supply roller 21 and the foil winder 11, and the amorphous alloy foil 51 is pressed by the pinch roller 28.

After that, the foil winder 11 side and the foil feeder 1
The amorphous alloy foil 51 is cut between the two by a cutting machine or the like manually or mechanically. At this time, since the amorphous alloy foil 51 on the fourth relay roller 24d is already pressed by the pinch roller 28 as described above, it is possible to prevent the amorphous alloy foil 51 from being rewound onto the material supply roller 21. Also, in the foil winder 11,
Since the pinch roller 18 presses the amorphous alloy foil 51 onto the magnetic core forming jig A1, it is possible to prevent winding collapse in the radial direction or the like. After that, the end of the winding end of the amorphous alloy foil 51 is manually fixed to a roll shape with an adhesive tape or the like, and then the pinch roller 18 is lifted to be separated from the magnetic core forming jig A1 to form a magnetic core forming jig. A
1 is removed from the support chuck 13 while the amorphous alloy foil 51 is still wound, and then the winding tools 1 and 2 are slid in the axial direction as shown in FIG. The work is finished.

As described above, since the winding of the amorphous alloy foil 51 is started after the end portions of the amorphous alloy foil 51 are held by the pair of winding tools 1 and 2, the winding repulsion causes disturbance of the winding. This can be prevented from occurring, and as a result, the diameter can be prevented from becoming large and the end can be prevented from hitting the operator's finger, arm, or the like to cause injury.

Further, at the time of cutting after the end of winding, the fourth relay roller 24 between the material supply roller 21 and the foil winder 11 is cut.
At d, the pinch roller 28 is used to form the amorphous alloy foil 51.
Since it holds down the amorphous alloy foil 5 after cutting
It is possible to prevent 1 from rewinding onto the material supply roller 21. Therefore, the end portion of the amorphous alloy foil 51 can be smoothly handled in the next winding operation. In the next winding operation, after manually pulling out the end of the amorphous alloy foil 51 to the foil winder 11 side, the pinch roller 28 is raised so that the amorphous alloy foil 51 does not come into contact with the pinch roller 28. Winding may be performed in this manner.

In the above embodiment, one side of the amorphous alloy foil 51 is coated with an insulating coating for magnetic insulation, and a slit is formed in the axial direction of the magnetic core 41 to prevent loss due to an eddy magnetic field. You may.

Further, the winding core half member 3 of the jig A1 for making a magnetic core
As for the above, a substantially cylindrical rod material has a diagonally divided shape, but a substantially prismatic or substantially elliptic rod material may have an obliquely divided shape.

[0037]

According to the first and fourth aspects of the invention, since the pair of winding core half members hold the end portion of the metal foil before starting the winding, the winding start It is possible to prevent the disorder of the winding due to the repulsive force, as a result,
It is possible to prevent the diameter from becoming large and the end from being injured by hitting the operator's finger or arm. Therefore, at the beginning of winding the amorphous alloy foil as the magnetic core, it can be uniformly and quickly carried out to improve productivity and quality stability, and also improve safety.

According to the invention described in claim 2, since each core half member is formed in a shape in which a substantially columnar bar member is obliquely divided from almost one end to almost the other end, the metal foil is formed. When the two core half members are removed after winding the magnetic core to form the magnetic core, it is sufficient to pull out both core half members from both ends of the metal foil toward the outside, and the removing work becomes extremely easy.

According to the third and fifth aspects of the invention, when the end portions of the metal foil supplied from the foil supply side are clamped by the clamping surfaces of both core half members, each core half member is held. The tip of
Only the positioning members on the other side of the core half members need to perform positioning, and the efficiency of the work of attaching the metal foil to the magnetic core producing jig is improved.

According to the sixth aspect of the present invention, since the metal foil is pressed by the pressing member in the axial direction at least when cutting the foil, it is possible to prevent the metal foil from being collapsed in the radial direction.

According to the invention described in claim 7, the cut end of the metal foil cut on the foil supply side is held near the installation position of the magnetic core making jig at least after cutting after winding. Since the member is pressed and fixed, it is possible to prevent the metal foil from rewinding to the foil supply side after cutting. Therefore, the end of the metal foil can be smoothly handled in the next winding operation.

According to the invention as set forth in claim 8, the quality of the magnetic core can be improved by appropriately adjusting the tension. In this case, since the end portions of the metal foil are sandwiched and wound by the pair of core half members, even if the strength of the tension is changed, the metal foil is disengaged from the magnetic core producing jig or the winding is disturbed. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic core producing jig according to an embodiment of the present invention.

FIG. 2 is a plan view showing a magnetic core production device and a magnetic core production jig according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a magnetic core production device and a magnetic core production jig according to an embodiment of the present invention.

FIG. 4 is a control block diagram showing each unit and a control unit according to an embodiment of the present invention.

FIG. 5 is a diagram showing a magnetic core creating operation according to the embodiment of the present invention.

FIG. 6 is a diagram showing a magnetic core creating operation according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional ignition coil.

FIG. 8 is a perspective view showing a magnetic core of a proposed example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st winding tool 2 2nd winding tool 3 Core half member 4 Quarter section 5 Positioning member 6 Insertion hole 11 Foil winder 12 Foil supply machine 13 Support chuck 14 Support stand 15 Slide bearing mechanism 16 Rotating device 17 Edge Control Device 18 Pinch Roller 20 Foil Feeder Main Body 21 Material Supply Roller 22 Supporting Member 23 Rotating Device 24a-24d Relay Roller 25 Tension Sensor 26 Tension Adjusting Brake 28 Pinch Roller 29 Rotary Encoder 30 Control Unit 31 Rotation Control Means 32 Tension Control means 33 Switching means A1 Magnetic core preparation jig A2 Magnetic core preparation device

Claims (8)

[Claims] 1. A magnetic core production jig for producing a magnetic core of an ignition coil by winding a metal foil made of a magnetic material, wherein the core forms a pair to wind the metal foil. A pair of core half members constituting the core core half member, the two core half members, a sandwiching surface for sandwiching the end portion of the metal foil between the other core half member is formed. Characteristic jig for core creation. 2. The jig for magnetic core production according to claim 1, wherein each of the winding core half members has a shape in which a substantially columnar bar member is obliquely divided from substantially one end portion to substantially the other end portion. A core-making jig, wherein the jig is formed so that the split cross section of each core half member is the sandwiching surface. 3. The magnetic core producing jig according to claim 1, wherein the core half members are positioned at the base end portions of the other core half members. A jig for magnetic core production, characterized in that members are fixed. 4. A method for producing a magnetic core of an ignition coil, which comprises winding the metal foil using the magnetic core producing jig according to claim 1 or 2, comprising: (a) supplying from a foil supply side. Holding the ends of the metal foil with the holding surfaces of the two core half members, and (b) rotating both metal core half members integrally around the central axis to wind the metal foil. A step of taking, (c) a step of cutting the metal foil from a foil supply side after the winding of the metal foil is completed, and a step of cutting the metal foil from the foil supply side to the outside from both ends of the metal foil. And a step of pulling out both of the winding core half members, respectively. 5. A method for producing a magnetic core for an ignition coil, comprising winding the metal foil using the magnetic core producing jig according to claim 3, comprising: (a) a metal foil supplied from a foil supply side. While abutting the ends of the core half members with the sandwiching surfaces of the core half members, the leading ends of the core half members are positioned by the positioning members fixed to the other core half members. And pressing the end portions of the two core cores by the holding surfaces of the two core half members, and (b) rotating the two core half members integrally around the central axis to wind up the metal foil. And (c) a step of cutting the metal foil from a foil supply side after completion of winding of the metal foil, and (d) after completion of winding of the metal foil, from both ends of the metal foil toward the outside. A method of producing a magnetic core for an ignition coil, comprising: pulling out both core half members. 6. The method for producing a magnetic core according to claim 4 or 5, wherein at least the step (c) comprises:
A method of producing a magnetic core for an ignition coil, comprising: pressing a cut end of the metal foil wound around the winding core half member in an axial direction with a predetermined pressing member. 7. The method for producing a magnetic core according to claim 4 or 5, wherein at least after the step (c), the cut end portion of the metal foil cut on the foil supply side is cut with the magnetic core. A method for producing a magnetic core of an ignition coil, which comprises pressing and fixing a predetermined holding member in the vicinity of an installation position of a lead making jig. 8. The method for producing a magnetic core according to claim 4 or 5, wherein in the step (b), the tension of the metal foil is detected by a predetermined tension detecting means and the tension is detected. At least one of the supply speed on the foil supply side and the rotation speed of the magnetic core preparation jig is adjusted by a predetermined tension adjusting means based on the detection result of the means, and a method for producing an ignition coil magnetic core. .