JP2016154215A - Line filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a line filter which enables terminals to be aligned with high accuracy and prevents deterioration of the reliability.SOLUTION: A case 50 is provided with: a first positioning part 56; a second positioning part 57; and a holding part 51 for fixing a normal mode core. The case 50 and a first bobbin are positioned by the first positioning part 56. The case 50 and a second bobbin are positioned by the second positioning part 57. The normal mode core is inserted into the holding part 51 to be fixed and form a closed magnetic circuit with a common mode core.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a line filter used for various electronic devices.

  For example, in the common mode choke coil 100 of Patent Document 1 as shown in FIG. 13, when a common mode (in-phase) noise current flows in the winding 101, magnetic flux is generated in the same direction in the magnetic core 102 by the winding. To do. This magnetic flux is consumed while circulating around the magnetic core 102. On the other hand, by providing the magnetic member 103, the effective magnetic permeability of the normal mode magnetic path is increased, and the magnetic flux is concentrated on the magnetic path (magnetic member and core member) having a large effective magnetic permeability. As a result, a normal mode inductance component is increased, and a common mode choke coil capable of removing strong normal mode noise can be obtained. When such a common mode choke coil is manufactured, there is a dimensional deviation between the magnetic core 102 and the magnetic member 103. Accordingly, a gap for absorbing the deviation is required between the magnetic core 102 and the magnetic member 103, the position of the magnetic member 103 varies, and the normal mode inductance varies. When the normal mode inductance is reduced, the noise removal effect is weakened. Conversely, when the normal mode inductance is increased, the magnetic core is likely to be magnetically saturated by the normal mode magnetic flux.

On the other hand, in order to solve the above-mentioned problem that the common mode choke coil of FIG. 13 has, Patent Document 2 discloses a common mode choke coil having the configuration shown in FIG.
In the common mode choke coil 110 of FIG. 14, two bobbins 111 having a cylindrical body, windings 112 a wound around the cylindrical body 112 of the bobbin 111, and holes in the cylindrical body 112 are formed. A magnetic core 113 for forming a normal mode magnetic path disposed between two adjacent bobbins 111, and a magnetic core 113 constituting a common mode closed magnetic path through which a leg portion is inserted; and At least one of the locations where the magnetic core 113 and the magnetic member 114 are in contact with each other, either the inner peripheral surface of the magnetic core 113 or the outer peripheral surface of the magnetic member 114 is provided with the magnetic core 113 and the magnetic member 114. A protrusion 115 is provided for relative positioning.

  Due to this protrusion, the variation in relative position between the magnetic core and the magnetic member is reduced, the effective permeability of the normal mode magnetic path becomes substantially constant, and the variation in normal mode inductance is suppressed. As a result, it is possible to obtain a common mode choke coil that is hardly magnetically saturated and has an excellent noise removal effect.

Japanese Patent Laid-Open No. 2003-224012 JP 2005-340670 A

However, since the magnetic core and the magnetic member are crushed by pressing the protrusions provided on the outer surface of the magnetic core or the magnetic member, there is a risk of the magnetic core and the magnetic member being cracked during assembly, There is a possibility that reliability may be lowered due to the possibility of cracking in the magnetic core and the magnetic member due to the residual stress generated by the pressing.
In addition, when assembling a common mode choke coil as in the conventional example, the two separate bobbins are positioned by the contact between the outer shape of the sintered core whose outer dimensions are likely to vary and the inner periphery of the bobbin. The terminals provided on the two separate bobbins are difficult to position with high precision, and it is difficult to enter the board hole into which the terminals are inserted, so that the mounting workability is deteriorated.

  Therefore, the present invention intends to provide a line filter that can solve the above-mentioned problems of the prior art.

In order to solve the above problems, the line filter of the present invention is:
A first cylindrical body portion around which a winding is wound, a first terminal block on which a first step portion is formed, a first bobbin made of a resin having a first terminal,
A second cylindrical body around which a winding is wound, a second terminal block on which a second step portion is formed, a second bobbin made of a resin having a second terminal,
A case made of a resin for positioning the first bobbin and the second bobbin in a state where the first cylindrical body and the second cylindrical body are arranged in parallel in the axial direction;
A common mode core in which legs are inserted into the first cylindrical body and the second cylindrical body to form a common mode closed magnetic path;
A normal mode core that forms a magnetic path of normal mode,
The case is provided with a first positioning portion, a second positioning portion, and a holding portion for fixing the normal mode core,
The first positioning portion is positioned with the first stepped portion, the second positioning portion is positioned with the second stepped portion, and the normal mode core is inserted into the holding portion and fixed to the common mode core. And a closed magnetic circuit is formed.

In the line filter of the present invention, as a further preferable feature,
“The holding portion is a bottomed rectangular cylindrical portion disposed between the first cylindrical barrel portion and the second cylindrical barrel portion,
The opening direction of the holding part is formed in a direction perpendicular to the axial direction of the first cylindrical body part and the second cylindrical body part. "
“The holding portion has a contact portion with which the normal mode core contacts in the insertion direction of the normal mode core, and when the normal mode core is inserted into the holding portion and contacts the contact portion, The magnetic flux between the common mode core and the normal mode core can be adjusted. "
“The upper end of the normal mode core is distributed below the same height as the upper end of the holding portion, or the same height as the upper ends of the flanges of the first bobbin and the second bobbin. Is included.

According to the line filter of the present invention, the first bobbin, the second bobbin, and the case are formed of a resin whose outer dimensions are unlikely to vary.
And since the 1st bobbin and the 2nd bobbin are positioned by the 1st positioning part and the 2nd positioning part of a case, it can position accurately between the terminals each provided in two separate bobbins.
Also, the common mode core legs are inserted into the first cylindrical body and the second cylindrical body positioned by the case, and the normal mode core is inserted and fixed into the holding part of the case. And a closed magnetic circuit is formed. Then, the relative position variation between the common mode core and the normal mode core can be relatively suppressed to reduce the variation in the normal mode core characteristics, and the normal mode core can be fixed without causing a crack in the holding portion. The reliability of the line filter is not reduced.

It is the line filter of the finished product of 1st Embodiment, (a) is a top view, (b) is a front view of arrow AA of (a), (c) is arrow B- of (a). A side view of B, (d) is a sectional view taken along the line CC of (a). It is a figure which shows the common mode core and normal mode core of 1st Embodiment, (a) is a front view of arrow AA in Fig.1 (a), (b) is an arrow view in Fig.1 (a). It is sectional drawing of CC. It is a separate bobbin in a 1st embodiment, (a) is a top view and (b) is a front view. It is a common mode core in 1st Embodiment, (a) is a top view, (b) is a front view. It is a normal mode core in 1st Embodiment, (a) is a top view, (b) is a front view. It is a case in 1st Embodiment, (a) is a top view, (b) is a front view. It is a top view in the state where a separate bobbin in a 1st embodiment was built in a case. It is the line filter of the finished product of 2nd Embodiment, (a) is a top view, (b) is a front view of arrow DD of (a), (c) is arrow E- of (a). The side view of E, (d) is sectional drawing of arrow FF of (a). It is a figure which shows the common mode core and normal mode core in 2nd Embodiment, (a) is a front view of arrow DD in FIG. 8 (a), (b) is an arrow view in FIG. 8 (a). It is sectional drawing of FF. It is the line filter of the finished product of 3rd Embodiment, (a) is a top view, (b) is a front view of arrow GG of (a), (c) is arrow view H- of (a). The side view of H, (d) is sectional drawing of the arrow II of (a). It is a figure which shows the common mode core and normal mode core in 3rd Embodiment, (a) is a front view of arrow GG in Fig.10 (a), (b) is an arrow view in Fig.10 (a). It is sectional drawing of II. This is a modification of the state before the separate bobbin in the first embodiment is assembled into the case, and convex portions 56a and 57a are provided on the lower surfaces of the first positioning portion 56 and the second positioning portion 57 of the case. 8 shows a state in which a concave portion (not shown) fitted to the portion is provided in the first step portion 35 and the second step portion 45 of the bobbin. It is sectional drawing which shows the common mode choke coil of a prior art example. It is sectional drawing which shows another common mode choke coil of a prior art example.

  Hereinafter, embodiments of the present invention will be exemplarily described based on the drawings.

(First embodiment)

  1 to 7, the line filter 1 in this embodiment includes a common mode core 10, a normal mode core 20, a first bobbin 30, a second bobbin 40, a case 50, and a fastener 60.

  As shown in FIG. 1 or FIG. 3, the first bobbin 30 and the second bobbin 40 are two separate bobbins made of a nonmagnetic thermosetting resin. The 1st bobbin 30 and the 2nd bobbin 40 were provided in the both sides of the 1st cylindrical trunk | drum 31, the 2nd cylindrical trunk | drum 41, the 1st cylindrical trunk | drum 31, and the 2nd cylindrical trunk | drum 41, respectively. A first winding 33 and a second winding 43 made of an insulating coated copper wire wound around the first flange 32, the second flange 42, the first cylindrical body 31 and the second cylindrical body 41. The first terminal block 34 and the second terminal block 44, the first terminal block 34 and the second terminal block 34 provided on both sides in the axial direction (Y direction) of the first cylindrical body 31 and the second cylindrical body 41. An I-type first terminal 36 and a second terminal 46 are fixed below the terminal block 44. The inside of the cross section of the first cylindrical body 31 and the second cylindrical body 41 is formed in a rectangular shape, and the cross-sectional outer shape of the leg portion 16 of the common mode core is the first cylindrical body 31 and the second cylindrical shape. It is formed in a rectangle that is slightly smaller than the inside of the cross section of the body portion 41. On the upper surfaces of the first terminal block 34 and the second terminal block 44, a first step portion 35 and a second step portion 45 are formed, which are positioned by positioning a first positioning portion 56 and a second positioning portion 57 described later. ing. Note that the first bobbin 30 and the second bobbin 40 may be formed of a thermoplastic resin.

  Each of the first winding 33 and the second winding 43 is wound around the outer circumference of the first cylindrical body 31 and the second cylindrical body 41 by one layer. Both ends of the first winding 33 are electrically connected to a first terminal 36 provided on the first bobbin 30. Both ends of the second winding 43 are electrically connected to a second terminal 46 provided on the second bobbin 40, respectively. The outer shapes of the first winding 33 and the second winding 43 are arranged inside the outer shape of the flange portion 32 of the first bobbin and the outer shape of the flange portion 42 of the second bobbin. Note that each of the first winding 33 and the second winding 43 may be wound in multiple layers.

  As shown in FIG. 4, the common mode core 10 includes two U-shaped cores 11. The core 11 includes an arm portion 12 and leg portions 16 that extend from both ends of the arm portion 12 in a perpendicular direction. Have.

  As shown in FIG. 5, the normal mode core 20 is formed in a T shape having two arm portions 21 and one leg portion 24A.

  Then, the leg portions 16 of the two cores 11 are respectively inserted into the first cylindrical body portion 31 and the second cylindrical body portion 41, and the tips of both leg portions 16 of the core 11 are the first cylindrical body portion 31. In the second cylindrical body 41, the core 11 is formed into an O-shape to form a common mode closed magnetic circuit. The arm upper end 13 of the common mode core is in contact with the inner upper surfaces of the first cylindrical body 31 and the second cylindrical body 41, and the common mode core 10 contacts the first bobbin 30 and the second bobbin 40. Fixed.

  As shown in FIG. 6, the case 50 is made of a nonmagnetic thermoplastic resin, and includes a bottomed square cylindrical portion 51, a first positioning portion 56, and a second positioning portion 57. Specifically, the case 50 includes a bottomed rectangular tubular part 51 having a side wall 53 and a bottom part 52, which are holding parts of the normal mode core 20, and an axial direction (Y direction) of the bottomed rectangular tubular part 51. Two first positioning portions 56 that protrude to the left from both ends and are positioned with the first stepped portion 35 of the first bobbin 30, and protrude from the upper and lower ends in the axial direction (Y direction) of the bottomed rectangular tubular portion 51 to the right. The second stepped portion 45 of the second bobbin 40 has two second positioning portions 57 that are positioned. Note that the case 50 may be formed of a thermosetting resin.

  As shown in FIG. 1 or FIG. 7, the bottomed rectangular cylindrical portion 51 of the case 50 is arranged between the first bobbin 30 and the second bobbin 40, and the first positioning portion 56 of the case 50 is the first positioning portion 56. The second positioning portion 57 of the case 50 is positioned on the second bobbin 40 while being positioned on the one bobbin 30. Specifically, the bottomed rectangular cylindrical portion 51 is disposed between the first cylindrical barrel portion 31 and the second cylindrical barrel portion 41, and the first cylindrical barrel portion and the second cylindrical barrel portion. The outer ends of the flange portions 32 and 42 are in contact with the side wall 53 of the bottomed rectangular cylindrical portion, and the first positioning portion 56 and the second positioning portion 57 are arranged on the first step portion 35 and the second step portion 45. And fixed by an adhesive. As a result, the first bobbin 30 and the second bobbin 40 are fixed to the case 50 in the XYZ directions of FIG. 1, and the first cylindrical body 31 and the second cylindrical body 41 are parallel to the case 50 in the axial direction. It is positioned.

  The opening direction of the bottomed rectangular cylindrical portion 51 is formed in a direction perpendicular to the axial direction of the first cylindrical barrel portion 31 and the second cylindrical barrel portion 41. Specifically, the opening direction of the bottomed rectangular cylindrical portion 51 is the insertion direction (Z direction) of the normal mode core 20 into the holding portion 51, and the tips of both leg portions 16 of the core 11 are the first cylindrical body. It is formed in a direction perpendicular to the axial direction inserted into the portion 31 and the second cylindrical body portion 41.

  Further, the opening of the bottomed rectangular tubular portion 51 is formed to be slightly larger than the outer shape of the leg portion 24A of the normal mode core inserted into the bottomed rectangular tubular portion 51.

In addition, the bottomed rectangular cylindrical portion 51 is formed with an outer shape guide portion 54 of a normal mode core. The outer shape guide part 54 is an axially opposite side part which is a part of the side wall 53 of the bottomed rectangular cylindrical part, and is arranged between the arm part 12 of the common mode core and the leg part 24A of the normal mode core.
In addition, on both side portions (outer shape guide portions) 54 in the axial direction, which are part of the side wall 53 of the bottomed rectangular cylindrical portion, a notch portion 54a (see FIG. 6B) provided at the upper end of the opening is provided. Yes.
Further, the length of the normal mode core leg portion 24A in the insertion direction is shorter than the length of the outer shape guide portion 54 in the insertion direction (see FIG. 1D).
Further, in FIG. 1D, in the state where the common mode core 10 is fixed integrally with the case 50, the outer shape guide portion 54 in the insertion direction is formed higher than the upper end 13 of the arm portion of the common mode core.

Further, the bottomed rectangular cylindrical portion 51 has a bottom portion (contact portion) 52. When the normal mode core 20 is inserted into the holding part 51 from the insertion direction, the lower end 23 of the arm part of the normal mode core has a bottomed rectangular tube shape before the leg part 24A of the normal mode core comes into contact with the contact part 52. The normal mode core 20 is positioned on the bottomed rectangular cylindrical portion 51 in contact with the outer shape guide portion 54 of the portion 51.
Then, the normal mode core 20 positioned in the bottomed rectangular cylindrical portion 51 of the case 50 is positioned in the insertion direction with the common mode core 10 fixed to the first bobbin 30 and the second bobbin 40.

That is, as shown in FIG. 1 (d), a bottomed rectangular cylindrical portion 51 is arranged in the O-type common mode core 10, and the normal mode core 20 is inserted into the bottomed rectangular cylindrical portion 51. ing. Then, the common mode core 10 and the normal mode core 20 are arranged with a gap.
In this example, as shown in FIG. 2A (when viewed from the arrow AA in FIG. 1A), the length of the normal mode core 20 in the insertion direction is equal to the common mode core 10 in the insertion direction. The common mode core 10 is arranged so as to be superimposed on the center of the normal mode core 20 in the insertion direction. Then, the magnetic paths of the common mode core 10 and the normal mode core 20 are, as shown in FIG. 2B, the arm upper end 13 of the common mode core, the arm lower end 23 of the normal mode core, and the arm of the common mode core. It is formed by the part side end 14, the leg part side end 25 of the normal mode core, the arm part lower end 15 of the common mode core, and the leg part side end 25 of the normal mode core. Further, the gap between the upper arm portion 13 of the common mode core and the lower arm portion 23 of the normal mode core is formed to be smaller than the gap between the arm side end 14 of the common mode core and the leg side end 25 of the normal mode core. .

  The stopper 60 is formed in a U shape, and is attached from the contact portion 52 side of the case 50 so as to sandwich the two cores 11 from the axial direction in order to bring the two cores 11 into close contact with each other.

Thus, the 1st cylindrical trunk | drum 31 by which the coil | winding was wound, the 1st terminal block 34 in which the 1st level | step-difference part 35 was formed, and the 1st bobbin 30 which consists of resin which has the 1st terminal 36, The second cylindrical body 41 around which the winding is wound, the second terminal block 44 in which the second step 45 is formed, the second bobbin 40 made of resin having the second terminal 46, the first A case 50 made of resin for positioning the first bobbin 30 and the second bobbin 40 in a state where the cylindrical body 31 and the second cylindrical body 41 are arranged in parallel to each other in the axial direction, and the first cylindrical body A leg portion is inserted into the portion 31 and the second cylindrical body portion 41 to form a common mode closed magnetic path, and a normal mode core 20 that forms a normal mode magnetic path.
Further, the first positioning portion 56 is positioned with the first step portion 35, the second positioning portion 57 is positioned with the second step portion 45, and the normal mode core 20 is inserted into the holding portion 51 and fixed to be common mode. The core 10 and a closed magnetic circuit are formed.

As described above, the first bobbin, the second bobbin, and the case are formed of a resin whose outer dimensions are unlikely to vary.
Then, since the 1st bobbin and the 2nd bobbin are positioned by the 1st positioning part and the 2nd positioning part of a case, it can position accurately between the terminals each provided in two separate bobbins. Therefore, it becomes easy to insert the terminal into the board hole into which the terminal is inserted, and the mounting workability is improved.
Further, the leg portions of the common mode core are inserted into the first cylindrical body portion and the second cylindrical body portion positioned by the case, and the normal mode core is inserted into the holding portion (bottomed rectangular cylindrical portion) of the case. It is inserted and fixed to form a common mode core and a closed magnetic circuit. Then, the relative position variation between the common mode core and the normal mode core can be relatively suppressed to reduce the variation in the normal mode core characteristics, and the normal mode core can be fixed without causing a crack in the holding portion. The reliability of the line filter is not reduced.
That is, the lower end 23 of the arm part of the normal mode core is in contact with the outer shape guide part 54 of the bottomed square cylindrical part 51, and the normal mode core 20 is positioned on the bottomed square cylindrical part 51. Then, the normal mode core 20 fixed to the bottomed rectangular cylindrical portion 51 of the case 50 is positioned in the insertion direction with respect to the common mode core 10 fixed to the first bobbin 30 and the second bobbin 40. As a result, the arm mode lower end 23 of the normal mode core can be accurately positioned in the insertion direction with the arm mode upper end 13 of the common mode core.
Further, in the configuration as in the conventional example, since the magnetic core is positioned by the protrusion of the magnetic member, there is a possibility that the impact resistance is lowered and the reliability is lowered.
On the other hand, the normal mode core is inserted into and fixed to the holding portion (bottomed rectangular cylindrical portion) of the case to form a closed magnetic circuit with the common mode core.
Then, the relative position variation between the common mode core and the normal mode core can be relatively suppressed to reduce the variation in the normal mode core characteristics, and the normal mode core can be fixed without causing a crack in the holding portion. The reliability of the line filter is not reduced.

  The holding part is a bottomed square cylindrical part arranged between the first cylindrical body part and the second cylindrical body part, and the opening direction of the holding part is the first cylindrical body part and the second cylindrical body part. Since it is formed in a direction perpendicular to the axial direction of the cylindrical body portion, the normal mode core can be fixed without contacting or cracking the common mode core by inserting the normal mode core into the holding portion.

(Second Embodiment)
Next, the configuration of the line filter according to the second embodiment of the present invention will be described with reference to FIG. 8 or FIG.
8 or 9, the same members as those in FIGS. 1 to 7 are denoted by the same reference numerals, and the description of these members is omitted.

In the first embodiment, the lower end 23 of the arm portion of the normal mode core is in contact with the outer shape guide portion 54 of the bottomed square tubular portion 51, and the normal mode core 20 is positioned on the bottomed square tubular portion 51. However, in the second embodiment, the leg portion 24B of the normal mode core is positioned in contact with the contact portion 52.
That is, in the first embodiment, in FIG. 1D, the outer shape guide portion 54 in the insertion direction is more than the upper end 13 of the arm portion of the common mode core in a state where the common mode core 10 is fixed integrally with the case 50. The length of the leg portion 24A of the normal mode core in the insertion direction is shorter than the length of the outer shape guide portion 54 in the insertion direction. In the second embodiment, FIG. In FIG. 5, in the state where the common mode core 10 is fixed integrally with the case 50, the outer shape guide portion 55 in the insertion direction is formed at the same height as the upper end 13 of the arm portion of the common mode core. The length of the portion 24B in the insertion direction is longer than the length of the outer shape guide portion 55 in the insertion direction.
When the normal mode core 20 is inserted into the holding portion 51 from the insertion direction, the lower end 23 of the arm portion of the normal mode core does not contact the outer shape guide portion 55, and the leg portion 24B of the normal mode core contacts the contact portion 52. Touch.

  In this example, the common mode core leg 16 is disposed in the first cylindrical body 31 and the second cylindrical body 41 to form a common mode closed magnetic circuit, and thus the normal mode core 20. Is inserted into the bottomed rectangular cylindrical portion 51 and abuts against the abutment portion 52, the gap between the upper end 13 of the common mode core and the lower end 23 of the normal mode core in the insertion direction can be adjusted. Characteristics can be adjusted, and variations in normal mode core characteristics can be reduced.

  Specifically, a plurality of normal mode cores 20 having different lengths from the arm lower end 23 to the leg lower end 26 of the normal mode core in the insertion direction are prepared. In this case, the total length of the normal mode core 20 in the insertion direction is changed without changing the length of the arm portion in the insertion direction. Then, one of the different normal mode cores is selected according to the required normal mode characteristics, and the normal mode core is inserted into the bottomed rectangular cylindrical portion 51 so that the lower end 26 of the leg of the normal mode core comes into contact with it. When abutting against the portion 52, the gap between the upper end 13 of the common mode core and the lower end 23 of the normal mode core in the insertion direction can be adjusted. As a result, the magnetic flux between the arm upper end 13 of the common mode core and the arm lower end 23 of the normal mode core in the insertion direction can be adjusted, the normal mode characteristics can be adjusted, and variations in the normal mode core characteristics can be reduced. .

  Even if one of the different normal mode cores is selected according to the required normal mode characteristics, the arm side end 14 of the common mode core, the leg side end 25 of the normal mode core, and the common mode core The magnetic flux between the arm portion lower end 15 and the leg portion side end 25 of the normal mode core does not change.

  In the configuration as in the conventional example, in order to adjust the gap between the magnetic core and the magnetic member in the insertion direction of the magnetic core, it is necessary to press and crush the magnetic core or the protrusion of the magnetic member. Therefore, it is considered that the normal mode characteristics cannot be easily adjusted.

  On the other hand, the holding portion 51 of this example has a contact portion 52 with which the normal mode core 20 contacts in the insertion direction of the normal mode core, and the normal mode core 20 is inserted into the holding portion 51 and contacts the contact portion 52. When in contact, the magnetic flux between the common mode core and the normal mode core can be adjusted by the gap between the upper end 13 of the common mode core and the lower end 23 of the normal mode core in the insertion direction of the normal mode core 20. In other words, multiple different normal mode cores are prepared, and one of the normal mode cores is selected according to the required normal mode characteristics, and the normal mode core is inserted into the holding portion and the contact portion By being in contact with and being fixed, the normal mode characteristics can be easily adjusted without causing cracks in the normal mode core, and variations in the normal mode core characteristics can be reduced.

  The normal mode core 20 of this example uses a T shape having two arm portions 21 and one leg portion 24B, and the T shape leg portion 24B is inserted into the holding portion 51 from the lower end portion 26 of the leg portion, When the lower end 26 comes into contact with the contact portion 52, the gap between the lower end 23 of the normal mode core and the upper end 13 of the common mode core in the insertion direction of the normal mode core 20 is set to adjust the normal mode characteristics. it can.

  The gap between the upper arm portion 13 of the common mode core and the lower arm portion 23 of the normal mode core is formed smaller than the gap between the arm side end 14 of the common mode core and the leg side end 25 of the normal mode core. . Then, when the gap between the arm upper end 13 of the common mode core and the arm lower end 23 of the normal mode core is formed larger than the gap between the arm side end 14 of the common mode core and the leg side end 25 of the normal mode core. Compared to the above, if the gap between the upper end 13 of the common mode core and the lower end 23 of the normal mode core is slightly adjusted, the magnetic flux between the upper end 13 of the common mode core and the lower end 23 of the normal mode core is greatly adjusted. It is possible to increase the adjustment range of the magnetic flux.

  Therefore, although the second embodiment is less difficult to suppress the relative position variation between the common mode core and the normal mode core than the first embodiment, the variation in the normal mode core characteristics can be reduced and the normal mode core can be reduced. Since the holding portion can be fixed without causing cracks, the reliability of the line filter is not lowered.

  Further, when the normal mode core 20 is inserted into the bottomed rectangular tubular portion 51 and comes into contact with the contact portion 52, the upper end 22 of the arm of the normal mode core is connected to the upper end of the opening of the bottomed rectangular tubular portion 51. The first bobbin 30 and the second bobbin 40 are disposed at the same height or less and at the same height or less as the upper ends of the flange portions 32 and 42 of the first bobbin 30 and the second bobbin 40.

  Then, since the normal mode core 20 is not arranged so as to protrude upward from the holding portion or the flanges of the first bobbin and the second bobbin, the completed line filter can be reduced in height, and the completed line filter can be placed on the ground. When dropped or when an impact is applied from the outside, the normal mode core is less likely to be chipped and reliability is not reduced.

(Third embodiment)
Next, the configuration of the line filter according to the third embodiment of the present invention will be described with reference to FIG. 10 or FIG.
10 or 11, the same members as those in FIGS. 1 to 9 are denoted by the same reference numerals, and the description of these members is omitted.

  The normal mode core 20 of the second embodiment is a T-type having two arms 21 and one leg 24B, but the normal mode core 27 of the third embodiment is formed in a square shape. It is what.

  As shown in FIG. 11 (a) (when viewed from the arrow GG in FIG. 10 (a)), the length of the normal mode core 27 in the insertion direction is longer than the length of the common mode core 10 in the insertion direction. The common mode core 10 is formed so as to be superimposed on the center of the normal mode core 27 in the insertion direction. Further, as shown in FIG. 11B, the magnetic path of the common mode core 10 and the normal mode core 27 includes the arm upper end 13 of the common mode core, the leg side end 28 of the normal mode core, and the common mode core. The arm portion side end 14, the normal mode core leg side end 28, the common mode core arm lower end 15, and the normal mode core leg side end 28 are formed.

In this example, when the normal mode core 27 is inserted into the bottomed rectangular tubular portion 51 and abuts against the abutment portion 52, the arm portion 12 of the common mode core and the side end 28 of the normal mode core The mode characteristics can be adjusted.
Specifically, a plurality of normal mode cores are prepared by changing only the length of the normal mode core in the insertion direction. Then, one of a plurality of normal mode cores is selected according to the required normal mode characteristics, the normal mode core is inserted into the bottomed rectangular cylindrical portion, and the lower end of the normal mode core is in contact with the contact portion. By being fixed in contact with each other, it is possible to adjust the magnetic flux between the arm portion upper end 13 of the common mode core and the side end 28 of the normal mode core, thereby adjusting the normal mode characteristics.

  Even if any one of a plurality of normal mode cores is selected according to the required normal mode characteristics, the magnetic flux at the arm side end 14 and the normal mode core side end 28 of the common mode core and the common mode core The magnetic fluxes at the lower end 15 of the core arm and the side end 28 of the normal mode core do not change.

  The third embodiment has the effects of the second embodiment and has a quadrangular shape excluding the T-shaped arm portion, so that the shape can be simplified and the cost can be reduced.

  The present invention is not limited to the embodiment described above, and can be variously modified within the scope of the gist thereof.

  In the above description, the normal mode core has a T shape and a quadrangular shape, but is not limited thereto. For example, the normal mode core may be a modified T type having one arm part and one leg part excluding one arm part from the T type, and the deformed T type leg part is inserted into the holding part from the lower end of the leg part. And may be fixed to form a magnetic path with the common mode core.

Also, in the description of the second and third embodiments, one of the different normal mode cores is selected according to the required normal mode characteristics, and the normal mode core is inserted into the holding portion and the contact portion. It is possible to adjust the normal mode characteristics by being in contact with and fixed to, but it is not limited to this.
For example, a normal mode core in which the length of the T-shaped arm portion 21 in the axial direction (Y direction) is changed may be used. Then, when one of the different normal mode cores is selected according to the required normal mode characteristics and the normal mode core is inserted into the bottomed rectangular cylindrical portion and fixed, the upper end of the arm of the common mode core The normal mode characteristics can be adjusted by the magnetic flux at the lower end of the arm of the normal mode core. In this case, the arm part of the normal mode core and the arm part of the common mode core are at least partially overlapped when viewed from the insertion direction.
Further, for example, a spacer (not shown) having a predetermined thickness is disposed in advance in the abutting portion in the bottomed rectangular cylindrical portion, and the normal mode core is abutted and fixed to the abutting portion via the spacer. It may be a thing. In this case, the normal mode characteristics can be adjusted by changing the thickness of the spacer according to the required normal mode characteristics.

  Further, in the above description, in FIG. 1D, the holding portion 51 is opened toward the left side of the drawing, and the leg portions 24A and 24B of the normal mode core are moved from the left side to the right side of the drawing. Although it is inserted into the opening and fixed in contact with the bottom 52 of the holding portion 51, the present invention is not limited to this. For example, FIG. 1D shows a case in which the holding portion 51 is opened toward the right side of the drawing, and the leg 24 of the normal mode core is inserted into the opening of the holding portion from the right side to the left side of the drawing. A configuration may be employed in which the bottom portion of the holding portion is in contact with and fixed (not shown). The stopper 60 in this case is attached from the bottom side of the holding portion so as to sandwich the two cores 11 from the axial direction.

  In the above description, the first positioning portion 56 and the second positioning portion 57 are arranged on the first step portion 35 and the second step portion 45 and are positioned by the adhesive, but as shown in FIG. Convex portions 56 a and 57 a are provided on the lower surfaces of the first positioning portion 56 and the second positioning portion 57, and unillustrated concave portions fitted to the convex portions 56 a and 57 a are the first step portion 35 and the second step portion 45. You may comprise so that it may be provided.

  In the above description, the first terminal 36 and the second terminal 46 are I terminals, but may be L terminals.

  Further, in the second embodiment, in FIG. 8D, in the state where the common mode core 10 is integrally fixed to the case 50, the outer shape guide portion 54 in the insertion direction is connected to the arm upper end 13 of the common mode core. The length in the insertion direction of the leg portion 24B of the normal mode core is formed to be longer than the length in the insertion direction of the outer shape guide portion 55, but is not limited thereto. In FIG. 8D, in the state where the common mode core 10 is fixed integrally with the case 50, the outer shape guide portion 54 in the insertion direction is formed at the same height as the arm portion upper end 13 of the common mode core. The length in the insertion direction of the leg portion 24B of the normal mode core may be shorter than the length in the insertion direction of the outer shape guide portion 55. In this case, when the normal mode core 20 is inserted into the holding portion 51 from the insertion direction, the arm lower end 23 of the normal mode core contacts the outer shape guide portion 55, and the arm lower end 23 of the normal mode core is the common mode core. The arm is fixed in contact with the upper end 13 of the arm.

DESCRIPTION OF SYMBOLS 1 Line filter 10 Common mode core 11 Core 12 Common mode core arm part 13 Common mode core arm upper part 14 Common mode core arm part side end 15 Common mode core arm lower part 16 Common mode core leg part 20 Normal Mode core 21 Normal mode core arm 22 Normal mode core arm upper end 23 Normal mode core arm lower end 24A Normal mode core leg 24B Normal mode core leg 25 Normal mode core leg side end 26 Normal Leg lower end of mode core 27 Normal mode core 28 Side end of normal mode core 30 First bobbin 31 First cylindrical body part 32 First cylindrical body part flange 33 First winding 34 First terminal block 35 First 1 step part 36 1st terminal 40 2nd bobbin 41 2nd cylindrical trunk | drum 42 The collar part of a 2nd cylindrical trunk | drum 43 Second Winding 44 Second Terminal Block 45 Second Step 46 Second Terminal 50 Case 51 Bottomed Square Cylindrical Part (Normal Mode Core Holding Part)
52 Bottom part of bottomed square cylindrical part (contact part)
53 Side Wall of Bottomed Square Cylindrical Portion 54 Both Sides in Axial Direction (External Shape Guide Portion) which is Part of Side Wall of Bottomed Square Cylindrical Portion
54a Notch portion 55 Both sides in the axial direction (outside guide portion) that are part of the side wall of the bottomed rectangular tubular portion
56 1st positioning part 56a Convex part 57 2nd positioning part 57a Convex part 60 Fastening metal fitting

Claims (4)

A first cylindrical body portion around which a winding is wound, a first terminal block on which a first step portion is formed, a first bobbin made of a resin having a first terminal,
A second cylindrical body around which a winding is wound, a second terminal block on which a second step portion is formed, a second bobbin made of a resin having a second terminal,
A case made of a resin for positioning the first bobbin and the second bobbin in a state where the first cylindrical body and the second cylindrical body are arranged in parallel in the axial direction;
A common mode core in which legs are inserted into the first cylindrical body and the second cylindrical body to form a common mode closed magnetic path;
A normal mode core that forms a magnetic path of normal mode,
The case is provided with a first positioning portion, a second positioning portion, and a holding portion for fixing the normal mode core,
The first positioning portion is positioned with the first stepped portion, the second positioning portion is positioned with the second stepped portion, and the normal mode core is inserted into the holding portion and fixed to the common mode core. A line filter characterized by forming a closed magnetic circuit. The holding part is a bottomed square cylindrical part disposed between the first cylindrical trunk part and the second cylindrical trunk part,
2. The line filter according to claim 1, wherein an opening direction of the holding part is formed in a direction perpendicular to the axial direction of the first cylindrical body part and the second cylindrical body part.   The holding portion has a contact portion with which the normal mode core contacts in the insertion direction of the normal mode core, and when the normal mode core is inserted into the holding portion and contacts the contact portion, the common The line filter according to claim 1, wherein a magnetic flux between the mode core and the normal mode core can be adjusted.   The upper end of the normal mode core is arranged below the same height as the upper end of the holding part, or is arranged below the same height as the upper ends of the flanges of the first bobbin and the second bobbin. The line filter according to claim 3.

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