JP7127317B2 - common mode choke - Google Patents

Description

The present invention relates to a common mode choke having an annular magnetic core, an annular case covering the magnetic core, and a plurality of conductors passing through a hollow portion of the case.

In motor driving, energy saving in motor driving is being promoted by converting power using a power converter such as an inverter. A power converter converts power by switching power semiconductors, but there is a problem that noise is generated from the switching of the semiconductors. Noise includes common mode noise and differential mode noise. Leakage current due to common mode noise in particular affects other devices, so countermeasures are important.
A common mode choke is used as a countermeasure against common mode noise. A common mode choke employs an annular magnetic core with a high magnetic permeability, such as a nanocrystalline soft magnetic material or Mn--Zn ferrite. As a common mode choke, there is a type in which an annular magnetic core is directly attached to the power supply wiring.

A conductor (copper plate) having a rectangular cross section called a bus bar is sometimes used as power supply wiring in an inverter or the like through which a large current flows, such as in a vehicle. When a plurality of busbars are used, a voltage is also applied between the busbars, so measures are taken to ensure insulation between the busbars.

For example, Patent Literature 1 discloses a technique related to a noise filter using a conductor penetration type magnetic core unit. Specifically, Patent Document 1 discloses an annular magnetic core made of a magnetic material, the inner circumference of which is penetrated by a bus bar, and an annular magnetic core made of a conductive material. a plurality of bus bars, each of which has a flat plate-like shape at least in part on the central side and passes through the hollow portion while being stacked in the plate thickness direction at predetermined intervals; A terminal block with a filter is disclosed, comprising: a molding member that integrally molds the bus bar with the terminal portion exposed.
In the busbars disclosed in Patent Document 1, two of the three busbars are bent to such an extent that they can be passed through the hollow portion of the annular magnetic core, and after these two busbars are meandering and passed through the magnetic core, the central straight busbars are inserted, and then an insulating bobbin is inserted between each busbar.

JP 2016-24939 A

The noise filter described in Patent Literature 1 uses a bus bar whose both end sides are bent. The reason for this is that if each busbar is straight, the ends of the busbars tend to be placed in the same space, and there is enough space to connect the ends of the busbars and the external conductors of the external electric circuit with bolts, etc. This is because the busbars are bent to secure a joint space between the two because the busbars cannot be separated from each other.

However, a through-conductor common mode choke is required to be easy to assemble. If the annular magnetic core is long in the axial direction, the bus bar cannot be passed through the hollow portion of the magnetic core if both ends of the bus bar are bent. It is conceivable to make the busbar thinner to give it elasticity so that the magnetic core can be easily penetrated.
Another method of penetrating the busbar through the annular magnetic core is to use an annular magnetic core that can be divided in the circumferential direction, for example, a magnetic core made up of a plurality of soft magnetic members having a U-shaped cross section so as to cover the midsection of the busbar. There is a method of combining soft magnetic members. However, with this method, it is difficult to divide the magnetic core when using a magnetic core integral in the circumferential direction, such as a wound magnetic core wound with an alloy ribbon. In addition, when it is divided, there is a problem that a magnetic gap is generated and the impedance characteristic is lowered.

In addition, the ends of the busbars are positioned at predetermined positions with respect to the magnetic cores to ensure the coupling with the external conductors.

In other words, it is desirable that the common mode choke should have a structure that takes into consideration the penetration of the busbar into the magnetic core and the positioning of the busbar ends, and that both operations can be performed with as simple an assembly as possible. However, it is very difficult to achieve both workability in the conventional conductor penetration type magnetic core unit.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a common mode choke that facilitates the penetration of the busbar into the magnetic core and the positioning of the end of the busbar relative to the magnetic core. .

The present invention is a common mode choke having an annular magnetic core, an annular case covering the magnetic core, and two busbars passing through a hollow portion of the case,
The bus bar has a resin portion in its midsection, and when viewed in the axial direction of the case, one end is bent to the outside of the hollow portion of the case and the other end is inside the hollow portion. ,
The two bus bars penetrate through the case so that the bent sides are arranged on different sides of the case, and are arranged in parallel in the hollow portion via the respective resin portions, It is characterized by being latched by the said case by the said resin part at the predetermined position of the said axial direction.
Further, the bus bar may be configured to be locked at the end of the case by a flange formed on the resin portion.
Moreover, in the axial direction of the case, the end portion of the resin portion may be located at a different position from the end portions of the other resin portions.
Further, the respective resin portions may be adjacent to each other within the hollow portion and may be in contact with the inner peripheral surface of the case.
Further, the resin portion and the case may have a structure in which a fitting portion capable of preventing the bus bar from coming off is formed at the contact portion.
Moreover, the annular magnetic core can be formed integrally in the circumferential direction.
Moreover, the said magnetic core and case can be set as the structure arranged in multiple numbers in the axial direction.
Further, the resin portion may be injection-molded in the midsection of the bus bar.

As described above, the common mode choke of the present invention can be simply assembled, and the bus bar can be easily passed through the annular magnetic core and the bus bar can be easily fixed.

It is an example of a common mode choke of the embodiment. 2 is a diagram showing a state in which a case and a resin portion of the common mode choke of FIG. 1 are combined; FIG. 2 is a diagram showing a resin portion of the common mode choke of FIG. 1; FIG. It is a figure which shows the cover part of the case of the common mode choke of embodiment. It is a figure which shows the bottom part of the case of the common mode choke of embodiment. It is a figure which shows the annular magnetic core of embodiment. It is a figure which shows the bus-bar of embodiment. It is a figure which shows the state which combined the case and the resin part in another embodiment. 9 is a diagram showing a resin portion used in FIG. 8. FIG. It is a figure which shows the case bottom part used in FIG. It is a figure which shows the state which combined the case and the resin part in another embodiment. FIG. 12 is a diagram showing a resin portion used in FIG. 11; FIG. 5 is a diagram for explaining the state of the end of the resin portion in the common mode choke of the embodiment; 1 is an example of a common mode choke of another embodiment; 15 is a diagram showing a busbar used in FIG. 14; FIG.

A common mode choke according to this embodiment will be described.
1 shows a common mode choke 10 of this embodiment, FIG. 1(a) is a front view, FIG. 1(b) is a bottom view, and FIG. 1(c) is a left side view.
This common mode choke 10 has annular cases 3a and 3b covering an annular magnetic core (not shown), and two bus bars 1a and 1b pass through the hollow portions of the cases 3a and 3b.
Further, the busbars 1a and 1b have resin portions (bobbins) 2a and 2b in their middle portions, and when viewed in the axial direction of the cases 3a and 3b, one end side (the busbar 1a in FIG. 1A) and the right end of the busbar 1b) are bent to the outside of the hollow part of the case, and the other end is inside the hollow part (see FIG. 1(c))
The two busbars 1a and 1b are penetrated through the case so that the bent sides are arranged on different sides of the cases 3a and 3b in the axial direction (the left end of the busbar 1a in FIG. 1A). , and the right end portion of the bus bar 1b), and are arranged in parallel in the hollow portion via the resin portions (bobbins) 2a and 2b, respectively, and the resin portions (specifically, the resin portions shown in FIG. The bobbin collar 21) is engaged with the case at a predetermined position in the axial direction.
Since the other end side of the bus bar is shaped to be able to pass through the hollow portion of the case, the bus bar can be easily passed through the inside of the magnetic core by inserting the other end side into the hollow portion.
In addition, since the bent sides of the busbar are arranged on different sides in the axial direction of the case, it is easy to connect the ends of the busbar and the external conductor.
Furthermore, since the resin portion is provided in the midsection of the busbar, the two busbars are arranged in the hollow portion via the resin portion, so that the busbars can be arranged apart from each other, and the insulation effect can be enhanced. can. It is preferable to use a resin having high insulating properties.
Further, since the resin portion is engaged with the case at a predetermined position in the axial direction, the bus bar can be easily positioned in the axial direction while allowing the bus bar to pass therethrough.
In addition, since the annular magnetic core is covered with the annular case, damage to the magnetic core due to external shock or the like can be suppressed.

The busbars 1a, 1b are locked at the ends of the cases (3a, 3b) by flanges (21 in FIG. 3) formed at one ends of the resin portions (bobbins) 2a, 2b.
According to such a configuration, it is possible to confirm that the bus bar is at the target position in the axial direction by visually confirming whether or not the flange portion and the case are in contact with each other, thereby facilitating the assembly work.
In addition, since the flange is formed on one bent end of the busbar, by inserting the other end of the busbar into the case and pushing it in as it is in one action, the flange contacts the end of the case, and the case and busbar are separated. Since the positioning is completed, the positioning work is easy.
In addition, since the collar is provided in a portion that does not pass through the hollow portion of the resin portion, it is easy to design the collar.

In the axial direction of the case, the end of the bobbin 2a or 2b may have a different position from the end of the other bobbins 2b or 2a. With such a configuration, the creepage distance between the busbars can be lengthened. Creepage distance is the shortest distance between two conductive parts measured along the surface of the insulator separating them. This creepage distance is used as an indicator of insulation between conductors. The reason is explained in detail below.
13 is a schematic diagram of an end portion of the case of FIG. 1; FIG. For the sake of explanation, the range in which the bobbin 2a exists is indicated by thick hatched lines, and the range in which the bobbin 2b exists is indicated by thin hatched lines. Also, the dimensions of each part are different from those in FIG.
When the ends of the bobbins 2a and 2b are at the same position, the creepage distance is the same distance W1 as the spatial distance between the busbars 1a and 1b. For example, the creepage distance can be lengthened by slanting the ends of the bobbin instead of aligning them perpendicularly to the longitudinal direction of the busbar, but the shape of the bobbin becomes complicated and molding becomes difficult. In particular, in the case of a common mode choke in which the distance between the busbars is 2 mm or less, the thickness of the resin portion sandwiched between the busbars is 1 mm or less, making it difficult to form a complicated shape.
As described above, by changing the position of the end of the bobbin, the length between the bent thick arrows can be made the creepage distance, and the creepage distance is much longer than the spatial distance W1 between the busbars 1a and 1b. You can keep your distance. Thereby, the insulation between bus bars can be improved.

The respective resin portions (bobbins) 2a and 2b can be configured to be adjacent to each other in the hollow portion and in contact with the inner peripheral surfaces of the cases (3a and 3b).
The common mode choke must have a structure capable of maintaining a differential mode such that the current flowing in each conductor cancels out the magnetic flux flowing in the magnetic core as much as possible. According to such a configuration, each resin portion is in contact with the inner peripheral surface of the case, thereby fixing the busbar in the direction perpendicular to the axis of the case, so that the busbar is positioned inside the case. As a result, the position of each busbar is fixed in the hollow part so as to keep a certain distance from the magnetic core, and the change in the amount of magnetic flux generated in the magnetic core due to the positional fluctuation of the busbar can be minimized. mode can be maintained.

The resin portions (bobbins) 2a and 2b and the cases 3a and 3b have a structure in which fitting portions (specifically, grooves 25 in FIG. 9, etc.) capable of preventing the busbar from coming off are formed at the portions where the two come into contact. can be
According to such a configuration, even after the busbar is inserted into the hollow portion of the case, it is possible to prevent the busbar from being displaced in the axial direction.

Moreover, the annular magnetic core (4 in FIG. 6) can be formed integrally in the circumferential direction.
Since the common mode choke of the present invention adopts such a configuration, it is easy to penetrate and position the bus bar without using a magnetic core divided in the circumferential direction. Both can be used as is.

Also, the resin portions (bobbins) 2a and 2b may be injection-molded on the midsections of the busbars 1a and 1b.
Injection molding has a large degree of freedom in molding, and facilitates molding of the above-mentioned collar portion and fitting portion. In addition, the dimensional accuracy of the molded collar portion and fitting portion can be increased. Therefore, the case and the busbar can be positioned more reliably.

Next, the present invention will be described in more detail, but the present invention is not limited by these examples.
(Example)
FIG. 1 is a diagram showing the appearance of a common mode choke 10 according to the present invention.
The common mode choke 10 includes two annular magnetic cores (not shown), annular cases 3a and 3b covering the respective annular magnetic cores, two busbars 1a and 1b, the busbars, and the busbar 1a. It consists of a bobbin 2a for insulating the cases 3a and 3b and a bobbin 2b for insulating the busbars and between the busbar 1b and the cases 3a and 3b.

Bus bars 1a and 1b are formed in the same shape. 7A and 7B are views showing a busbar, FIG. 7A being a front view of the busbar, and FIG. 7B being a side view thereof. Bus bars 1a and 1b have a rectangular cross section. In addition, holes 11 are formed at both ends for connection to external conductors with bolts. In addition, a straight midsection with a resin portion injection molded is formed in the center, and the conductors are exposed at both end portions where the resin portion is not formed. One end side is bent at a bent portion 12, and the maximum width in the vertical direction in FIG. is also big. Moreover, the other end side is formed linearly.
The material of the bus bar is copper with a conductivity of 96% or more. Also, the cross-sectional area S (mm ² ) of the bus bar can be determined by dividing the current capacity (A) to be used by the current density (A/mm ² ). For the current density, for example, JIS standard 8480 defines values for current capacities classified into a plurality of ranks. Along with the cross-sectional area of the busbar, the size of the magnetic core is determined.

The bobbins 2a, 2b are formed in the same shape, and are resin members fixed to the midsections of the busbars 1a, 1b. In this embodiment, the resin member is molded by injection molding. However, FIG. 3 describes the state of a single bobbin for the sake of explanation.
FIG. 3 is a perspective view of the bobbin 2a, FIG. 3(a) is a view of the bobbin as seen obliquely from above, and FIG. 3(b) is a view of the bobbin as seen from the opposite direction to FIG. 3(a). The bobbins 2a and 2b are semi-cylindrical and have an arc-shaped outer peripheral surface 23 and a planar contact portion 24. As shown in FIG.
Also, the bobbins 2a and 2b have through holes 22 to which busbars are fixed. Since the bobbins 2a and 2b cover the middle portions of the busbars, the busbars 1a and 1b can maintain an insulating state while being arranged in the hollow portion of the case. Also, even if one of the bobbins is cracked, the other bobbin can maintain the insulating state.
The material of the bobbin can be, for example, a thermoplastic resin (eg, PBT resin, PET resin) or the like, and if necessary, glass fibers can be added to increase the mechanical strength.
Furthermore, the bobbins 2a and 2b are formed with a collar 21 on one end side. The brim 21 is a semicircular plate having a through hole for the bus bar, and the semicircle has a larger diameter than the hollow portion of the case. This collar serves to fix the bobbin in a predetermined axial position with respect to the case. The shape of this brim 21 is not particularly limited, and the maximum width should be larger than the diameter of the hollow portion of the case.
The bobbins 2a and 2b have a columnar shape by having the planar contact portions 24 opposed to each other and adjacent to each other. The bobbins 2a and 2b are adjacent to each other in the hollow portion so that the collars of the bobbins 2a and 2b are located on different end sides.

The widest plane portions of the busbars 1a and 1b are fixed in the bobbins so as to be parallel to the planes of the contact portions 24 of the bobbins 2a and 2b. Therefore, by arranging the contact portions 24 of the bobbins 2a and 2b to face each other and adjoin each other, the busbars 1a and 1b become parallel to each other. can be increased, that is, the effective cross-sectional area through which the current of the busbar in the hollow portion passes can be increased. Therefore, this bus bar and bobbin can contribute to the manufacture of common mode chokes that can easily handle large currents.
Also, the busbar is fixed so that both ends of the busbar protrude from the bobbin. The bent portion formed on one end side of the busbar is arranged on the side of the bobbin where the flange is provided.
With such a configuration, the busbars can be passed through the magnetic core simply by inserting the linear end portions of the busbars 1a and 1b into the inner diameter portion of the case. Further, since the bobbin collar is engaged with the case, the bus bar and the magnetic core can be fixed at a predetermined position in the axial direction simply by inserting the bobbin into the case.

An annular case will be described. FIG. 4 is a perspective view of the lid portion 31 of the case, and FIG. 5 is a perspective view of the bottom portion 32 of the case. In the figure, broken lines indicate the outline of the inside of the case. In addition, in the lines extending from the figure numbers, the thin lines with black dots on the tip side indicate the parts inside the case.
A lid-side hollow portion 311 is formed in the lid portion 31 of the case. Further, a doughnut-shaped lid groove 312 capable of accommodating a part of the annular magnetic core is formed inside, and a step 313 for combining with the bottom portion 32 is formed on the opening side (lower side in the drawing). ing.
A bottom-side hollow portion 321 is formed in the bottom portion 32 of the case. Further, a doughnut-shaped bottom groove 322 capable of accommodating a part of the annular magnetic core is formed inside, and a step 323 for combining with the lid portion 31 is formed on the opening side (upper side in the drawing). ing.

The case 3 is a combination of a lid portion 31 and a bottom portion 32, and has an annular appearance. A cylindrical hollow portion is formed on the inner diameter side of the assembled case 3 . The diameter of the hollow portion is set so that the bobbins 2a and 2b can be inserted adjacent to each other, and the inner peripheral surface and the outer peripheral surface 23 of the bobbins 2a and 2b can slide. be done.

The material of the case can be, for example, a thermoplastic resin (eg, PBT resin, PET resin) or the like, and if necessary, glass fibers can be added to increase the mechanical strength.
In the common mode choke of this embodiment, two cases containing magnetic cores are coaxially connected and used.

An annular magnetic core will be described. 6 is a perspective view of the magnetic core 4. FIG. The magnetic core 4 is formed in an annular shape.
This magnetic core can be made of a known soft magnetic material. For example, it can be produced by powder molding a ferrite material, or by winding an amorphous metal ribbon or a nanocrystalline metal ribbon.
In this embodiment, a magnetic core obtained by winding a nanocrystalline amorphous metal ribbon (thickness of 25 μm) to form a laminate and heating it to a temperature equal to or higher than the crystallization start temperature to nanocrystallize is used.
The magnetic core 4 is accommodated in the space formed by the bottom groove 322 of the case bottom portion 32 and the lid groove 312 of the case lid portion 31 . By preventing the magnetic core 4 from moving inside the case, it is possible to fix the distance from the bus bar fixed to the case via the resin portion. In order to fix this distance, it is possible to design so that the space in the case and the magnetic core 4 are fitted. Also, the magnetic core 4 and the case can be fixed with an adhesive or the like.

A method of fixing the busbar will be described in further detail.
The busbar 1a is fixed to the cases 3a and 3b via the bobbin 2a, and the busbar 1b is fixed to the cases 3a and 3b via the bobbin 2b.
FIG. 2 is a perspective view showing an upper body in which bobbins 2a and 2b and cases 3a and 3b containing magnetic cores are combined. In the drawing, the appearance of the bobbin inside the case is indicated by a dashed line.
The bobbins 2a, 2b are inserted into the hollow portions of the cases 3a, 3b arranged in the axial direction. The bobbin 2a is inserted into the hollow portion of the case from one axial end to the end without a flange until the flange 21 abuts against the axial end of the case. The collar 21 locks the bobbin 2a to the case at a predetermined position in the axial direction. After the bobbin 2a is inserted, the bobbin 2b is inserted from the other end of the case from the end without the collar.
The bobbins 2a and 2b are formed in a columnar shape by adjoining each other with their flat portions opposed to each other, and the outer peripheral surfaces thereof are designed to slide against the inner peripheral surfaces of the hollow portions of the cases 3a and 3b. Therefore, the positions of the inserted bobbins 2a and 2b are fixed with respect to the magnetic core not only in the axial direction but also on the axial cross section.

FIG. 13 is an enlarged view of the case end side of FIG. In the common mode choke of this embodiment, the end 2a or 2b of the resin portion is located in a different position from the other end of the resin portion 2b or 2a in the axial direction of the case, so there is a step between them. This increases the creepage distance and enhances the insulation between the busbars.
Moreover, since this step can be formed by the flange portion 21 for locking the busbar to the case, it is possible to fix the busbar and increase the creepage distance with a simple configuration.

Another embodiment of the present invention will be described below. Structures that overlap with the above description may be omitted.

8 to 10 are diagrams showing an embodiment in which a fitting portion capable of preventing the bus bar from coming off is formed at the portion where the resin portion and the case are in contact with each other.
The magnetic core shown in FIG. 6 and the bus bar shown in FIG. 7 can be used.
FIG. 10 is a top view and a side view of the case bottom portion 32c used in this embodiment. It differs from the bottom portion 32c of FIG. 5 in that a convex portion 324 is formed on the inner peripheral surface of the hollow portion 321, and the rest is the same.
FIG. 9 shows the bobbin used in this embodiment. The bobbins 1a and 1b of FIG. The groove portion 25 is formed on the outer peripheral surface 23 and is formed slightly deeper than the height of the convex portion 324 of the bottom portion 32c of the case. The groove portion 25 is composed of one linear groove extending in the axial direction from the end on the side where the flange portion 21 is not formed and two circumferential grooves extending in the circumferential direction thereof. The two circumferential grooves are located at positions where the projections 324 of the bottom portion 32c are formed with the collar portion 21 locked to the case.

A method for positioning the bobbin (bus bar) and the case in the axial direction and a fitting method for preventing the bus bar from coming off will be described with reference to FIG.
Since the bobbin is fixed to the busbar, if the bobbin does not come off from the case, the busbar will not come off either.
The bobbins 2c and 2d are inserted into the hollow portions so that the convex portions 324 of the cases 3c and 3d slide with the groove portions 25. As shown in FIG. The bobbin 2c is inserted into the hollow portion of the case from one axial end side until the flange 21 abuts against the axial end of the case. The collar 21 locks the bobbin 2c to the case at a predetermined position in the axial direction. After the bobbin 2c is inserted, the bobbin 2d is inserted from the other end of the case from the end without the flange.
The inserted bobbins 2c, 2d are rotated relative to the cases 3c, 3d. As a result, the convex portion 324 of the case moves from the linear groove of the groove portion 25 to the circumferential groove. In this state, the convex portion 324 of the case is engaged with the axial wall surface of the circumferential groove, and the bobbins 2c, 2d and the cases 3c, 3d are fitted. In addition to the effect of the bobbin shown in FIG. 3, such a structure has the effect of preventing the bobbin and bus bar from coming off.

In another embodiment, the bobbin flange 21 may be removed, and the protrusion 324 of the case and the end wall of the groove 25 may be engaged to position the case and the bobbin in the axial direction.
According to such a configuration, it is possible to position the case and the bobbin in the axial direction and to prevent the bus bar from falling off only by the groove, and the collar of the bobbin can be eliminated, so that the weight can be reduced. Also, since the shape is simplified, it is easy to manufacture the bobbin.
Also in this embodiment, the creepage distance can be increased by designing the end of the resin portion to be located at a different position from the end of the other resin portions in the axial direction of the case.

11 and 12 are diagrams showing still another embodiment, in which the cross-sectional shape of the bobbin is different.
The magnetic core shown in FIG. 6 can be used. The bus bar shown in FIG. 7 and the case shown in the lid portion of FIG. 4 and the bottom portion of FIG. 10 can be used.
FIG. 12 shows the bobbin used in this embodiment. The bobbins 2c and 2d shown in FIG. 9 differ from each other in that a part of the outer peripheral surface 23 serves as a side wall 26, and the rest is the same. The positioning method in the axial direction and the fitting method for preventing the bus bar from coming off are the same as those explained in FIG.
The bobbins 1e and 1f shown in FIG. 12 are adjacent to each other in the hollow portions of the cases 3c and 3d, and the outer peripheral surface 23 is in contact with the inner peripheral surface of the case, but the side wall 26 is not in contact. According to such a configuration, in addition to the effects of the bobbins 1c and 1d shown in FIG. 9, the thickness of the side surface of the through hole 22 is reduced, resulting in weight reduction and material cost reduction.

Also in this embodiment, a structure in which the bobbin flange 21 is eliminated and the case projection 324 and the end wall of the groove 25 are engaged to position the case and the bobbin in the axial direction can be adopted.
Also in this embodiment, the creepage distance can be increased by designing the end of the resin portion to be located at a different position from the end of the other resin portions in the axial direction of the case.

14 and 15 are diagrams showing still another embodiment, in which the shape of the busbar is different from that of the common mode choke of FIG. The axial positioning method and the fitting method for preventing the bus bar from coming off are also the same as those explained in FIG.
FIG. 15 shows a busbar used in this embodiment. The busbars 1a and 1b in FIG. 7 are formed so that both the tip side and the central side of the bent portion 12 are in the same plane, whereas the busbar in FIG. 12 is bent at the position of the bent portion 12. is formed as According to such a configuration, the busbar of FIG. 15 can be formed simply by bending the bent portion, and is easy to manufacture.

1: busbar, 2: bobbin, 3: bobbin (resin portion), 4: magnetic core, 10: common mode choke, 11: hole (busbar), 12: bent portion (busbar), 21: collar portion (bobbin), 22 : through hole (bobbin), 23: outer peripheral surface (bobbin), 24: contact portion (bobbin), 25: groove portion (bobbin), 26: side wall (bobbin), 31 cover portion (case), 32: bottom portion (case) , 311, 321: hollow portion (case), 312: cover groove, 322: bottom groove, 313: step, 324: convex portion

Claims (7)

An annular magnetic core, an annular case covering the magnetic core, and a common mode choke in which two busbars pass through a hollow portion of the case,
The bus bar has a resin portion in its midsection, and when viewed in the axial direction of the case, one end is bent to the outside of the hollow portion of the case and the other end is inside the hollow portion. ,
The resin portion has a flange protruding from the case at one end in the axial direction of the case, is locked at the end of the case by the flange, and extends to the end of the case at the other end. is growing,
The resin portion includes a planar contact portion,
The resin portion of the first bus bar and the resin portion of the second bus bar are housed in the case adjacent to each other with the planar contact portions facing each other,
The two busbars penetrate through the case so that bent sides are arranged on different sides of the case in the axial direction, and
are arranged in parallel within the hollow portion via the respective resin portions,
The resin portion is engaged with the case at a predetermined position in the axial direction ,
A common mode choke , wherein the widest plane portion of the bus bar is parallel to the plane of the contact portion of the resin portion . 2. The common mode choke according to claim 1 , wherein the end of the resin portion is located at a different position from the ends of the other resin portions in the axial direction of the case. 3. The common mode choke according to claim 1, wherein the respective resin portions are adjacent to each other in the hollow portion and are in contact with the inner peripheral surface of the case. 4. The common mode choke according to claim 3 , wherein the resin portion and the case are formed with a fitting portion capable of preventing the bus bar from coming off at the contact portion. 5. A common mode choke according to claim 1 , wherein said annular magnetic core is integrally formed in the circumferential direction. 6. The common mode choke according to claim 1 , wherein a plurality of said magnetic cores and cases are arranged in the axial direction. 7. The common mode choke according to any one of claims 1 to 6 , wherein the resin portion is injection-molded in the midsection of the bus bar.

Images