Patent Description:
Patent Document <NUM> describes a noise filter as a measure against noise radiated from a conductive busbar. The noise filter includes a magnetic core having a through-hole, and is used by passing the busbar through the through-hole of the magnetic core.

A bent-shaped busbar may be used in consideration of routing of the busbar in a device. When the bent-shaped busbar is attempted to be inserted into the through-hole of the magnetic core, the bent portion in the busbar interferes with an opening edge portion of the through-hole, and the busbar cannot pass through the through-hole in some cases. In such a case, for example, it is considered that a configuration in which an inner diameter dimension of the through-hole of the magnetic core is increased or a configuration in which the magnetic core has a divided structure is employed to cause the bent-shaped busbar to pass through the through-hole of the magnetic core. However, the larger the inner diameter dimension of the through-hole is, the lower an impedance of the magnetic core becomes, and therefore a noise reduction effect of the noise filter decreases. With the magnetic core having the divided structure, a magnetic permeability of the magnetic core decreases, thus reducing the noise reduction effect of the noise filter.

The present disclosure preferably provides a noise filter that is less likely to reduce a noise reduction effect while increasing a degree of freedom in a busbar shape in a device.

A noise filter according to an aspect of the present disclosure includes a non-divided type magnetic core, a conductive coupling terminal, and a holding portion. In the non-divided type magnetic core, a through-hole having a first opening and a second opening at respective ends of the through-hole is formed. The conductive coupling terminal includes a first connection portion and a second connection portion at respective ends of the conductive coupling terminal. The first connection portion and the second connection portion are connectable to busbars. The conductive coupling terminal is disposed inside the through-hole. The holding portion holds the coupling terminal disposed inside the through-hole. The coupling terminal is held to the magnetic core by the holding portion in a state where the first connection portion faces the first opening from inside of the through-hole and the second connection portion faces the second opening from inside of the through-hole.

In the configuration described above, the conductive coupling terminal having the first connection portion and the second connection portion connectable to the busbars at respective ends is disposed in the through-hole integrally formed with the magnetic core. The coupling terminal is held to the inside of the through-hole by the holding portion in the state where the first connection portion faces the first opening from inside of the through-hole and the second connection portion faces the second opening from inside of the through-hole in an extending direction of the through-hole. As a result, among a set of the busbars, a first busbar is connected to the first connection portion through the first opening of the through-hole and a second busbar is connected to the second connection portion through the second opening of the through-hole, and thus both busbars can be coupled. Therefore, even when the non-divided type magnetic core is used, a signal flowing through the first busbar can be passed through the through-hole of the magnetic core and flow to the second busbar regardless of a bent shape of the busbar. As a result, the noise filter can be less likely to reduce a noise reduction effect while increasing a degree of freedom in the busbar shape in a device.

The noise filter according to an aspect of the present disclosure may include a case made of a non-conductive resin and housing the magnetic core. The case may include a through-portion having a tubular shape. The case may house the magnetic core in a state where the through-portion passes through the through-hole. The coupling terminal may be disposed inside the through-portion.

In the noise filter according to an aspect of the present disclosure, the holding portion may include a housing portion disposed inside the through-hole. The housing portion may house the coupling terminal to hold the coupling terminal. This allows the coupling terminal to be held in the through-hole while the coupling terminal maintains insulation properties with the magnetic core. Thus, while a signal is appropriately transmitted between the busbars, the noise reduction effect of the noise filter can be less likely to be reduced.

In the noise filter according to an aspect of the present disclosure, the holding portion may include a locking portion. The locking portion may be disposed inside the through-hole to lock the holding portion to the magnetic core. This enhances a fixing force of the holding portion with respect to the magnetic core to ensure that the coupling terminal is reliably positioned in the through-hole of the magnetic core. For example, even when an external force is applied to the coupling terminal via the busbar, it can be suppressed that the coupling terminal is pulled out of the through-hole of the magnetic core, and reduction in noise reduction effect of the noise filter can be suppressed.

One aspect of the present disclosure may include a case made of a non-conductive resin and housing the magnetic core. The holding portion may be disposed inside the through-hole and integrally formed with the case. As a result, in the noise filter provided with the case, an increase in the number of components can be suppressed while effects of the present disclosure are provided.

The present disclosure can provide the noise filter that is less likely to reduce a noise reduction effect of the noise filter while increasing a degree of freedom in a busbar shape in a device.

The following will describe embodiments of a noise filter with reference to the drawings. Note that, in the following description, respective directions illustrated in the drawings are used for explanation as needed. Specifically, a direction in which a through-hole of a magnetic core extends is a first direction, and respective directions orthogonal to the first direction is referred to as a second direction and a third direction. However, these respective directions are defined only for the purpose of facilitating descriptions of relative positional relationship of respective portions constituting the noise filter. To actually use the noise filter, the noise filter may be oriented in any direction. For example, the noise filter may be used in a state where the third direction illustrated in the drawing does not match the vertical direction due to the relationship of the third direction with gravity.

A noise filter <NUM> illustrated in <FIG> and <FIG> is a device connected to busbars <NUM>, <NUM>, <NUM>, and <NUM> to reduce radiation of noises from the busbars <NUM> to <NUM>. Specifically, the noise filter <NUM> couples a set of the busbars <NUM> and <NUM>, and relays a signal flowing from a circuit (not illustrated) to the busbar <NUM> to the busbar <NUM> while causing the signal to pass through a through-hole of a magnetic core <NUM>. The noise filter <NUM> couples a set of the busbars <NUM> and <NUM>, and relays a signal flowing from the circuit (not illustrated) to the busbar <NUM> to the busbar <NUM> while causing the signal to pass through the through-hole of the magnetic core <NUM>.

In the present embodiment, each of the busbars <NUM> to <NUM> has bent flat plate pieces to form an attachment seat portion, an extension portion, and an insertion portion. Attachment seat portions 101a, 102a, 103a, and 104a are portions each having a through-hole. Terminal fixing bolts pass through the through-holes for fixing the busbars <NUM> to <NUM> to a device. In the present embodiment, each of the attachment seat portions 101a to 104a has a surface parallel to a plane defined in a first direction D1 and a second direction D2. Extension portions 101b, 102b, 103b, and 104b are portions that connect the attachment seat portions 101a to 104a and insertion portions 101c to 104c of the busbars <NUM> to <NUM>, respectively. In the present embodiment, the extension portions 101b to 104b are portions bent in specified directions with respect to the attachment seat portions 101a to 104a and the insertion portions 101c to 104c. The insertion portions 101c, 102c, 103c, and 104c are portions connected to coupling terminals <NUM> and <NUM> included in the noise filter <NUM>.

In addition to the magnetic core <NUM> described above, the noise filter <NUM> includes the coupling terminals <NUM> and <NUM> and a holding portion <NUM>. <FIG> is a cross-sectional view of the magnetic core <NUM> in a surface along the first direction D1. The magnetic core <NUM> is a ring-shaped non-divided type magnetic core having end surfaces <NUM> and <NUM>. A through-hole <NUM> is formed in the magnetic core <NUM>. The through-hole <NUM> is a through-hole extending from an opening <NUM> formed in the first end surface <NUM> of the magnetic core <NUM> to an opening <NUM> formed in the second end surface <NUM>. For the magnetic core <NUM>, for example, a soft ferrite as a soft magnetic material or a nanocrystalline soft magnetic material mainly containing a fine metal can be used. As the nanocrystalline soft magnetic material, for example, FINEMET (registered trademark) can be used.

Next, the configuration of the holding portion <NUM> will be described. As illustrated in <FIG>, <FIG>, and <FIG>, the holding portion <NUM> is a member that holds the coupling terminals <NUM> and <NUM> inside the through-hole <NUM> of the magnetic core <NUM>. The holding portion <NUM> includes a housing portion <NUM> that houses the coupling terminals <NUM> and <NUM> and a set of locking portions 65a and 65b.

The housing portion <NUM> is a container that houses the coupling terminals <NUM> and <NUM> in a state of being arranged along the second direction D2. Specifically, a housing space <NUM> that houses the coupling terminal <NUM> and a housing space <NUM> that houses the coupling terminal <NUM> are formed inside the housing portion <NUM>. As illustrated in <FIG>, the housing space <NUM> extends in the housing portion <NUM> from an opening <NUM> formed at a first end portion in the first direction D1 to an opening <NUM> formed at a second end portion in the first direction D1. As illustrated in <FIG>, the housing space <NUM> extends in the housing portion <NUM> from an opening <NUM> formed at the first end portion in the first direction D1 to an opening <NUM> formed at the second end portion in the first direction D1.

In the present embodiment, the housing portion <NUM> includes a container body <NUM>, a first lid portion <NUM>, and a second lid portion <NUM>. The housing portion <NUM> is configured by assembling the container body <NUM>, the first lid portion <NUM>, and the second lid portion <NUM>. <FIG> is a cross-sectional view of the container body <NUM> in a surface parallel to the second direction D2 and a third direction D3. <FIG> is a cross-sectional view of the first lid portion <NUM> in the surface parallel to the second direction D2 and the third direction D3. <FIG> is a cross-sectional view of the second lid portion <NUM> in the surface parallel to the second direction D2 and the third direction D3.

As illustrated in <FIG>, the container body <NUM> has a partition wall portion <NUM>, which is a rectangular wall, and side wall portions <NUM> and <NUM> provided at respective ends in the third direction D3 of the partition wall portion <NUM>. Specifically, the side wall portions <NUM> and <NUM> extend in the second direction D2 from respective ends in the third direction D3 of the partition wall portion <NUM>, and have substantially H-shaped cross-sectional surfaces in planes defined in the second direction D2 and the third direction D3. In other words, as illustrated in <FIG>, a first recessed portion <NUM> having a first surface in the third direction D3 of the partition wall portion <NUM> as a bottom surface 621a is formed in the container body <NUM>. Additionally, a second recessed portion <NUM> having a second surface in the third direction D3 of the partition wall portion <NUM> as a bottom surface 621b is formed in the container body <NUM>. Holding protrusions <NUM> protruding in the second direction D2 are provided on the bottom surface 621a of the partition wall portion <NUM>, and holding protrusions <NUM> protruding in the second direction D2 are provided on the bottom surface 621b of the partition wall portion <NUM>. The container body <NUM> is non-conductive and made of, for example, a polyamide resin.

As illustrated in <FIG>, the first lid portion <NUM> has a rectangular base portion <NUM> and side wall portions <NUM> and <NUM> extending from respective ends in the third direction D3 of the base portion <NUM>. Holding protrusions <NUM> protruding in the second direction D2 are provided on the back surface facing the container body <NUM> of the base portion <NUM>. The first lid portion <NUM> is non-conductive and made of, for example, a polyamide resin. As illustrated in <FIG> and <FIG>, a flange <NUM> that protrudes outward from the base portion <NUM> and the side wall portions <NUM> and <NUM> is formed at an end in the first direction D1 of the first lid portion <NUM>.

As illustrated in <FIG>, the second lid portion <NUM> has a rectangular base portion <NUM> and side wall portions <NUM> and <NUM> extending from respective ends in the third direction D3 of the base portion <NUM>. Holding protrusions <NUM> protruding in the second direction D2 are provided on the back surface, which is a surface facing the container body <NUM>, of the base portion <NUM>. As illustrated in <FIG> and <FIG>, a flange <NUM> that protrudes outward from the base portion <NUM> and the side wall portions <NUM> and <NUM> is formed at an end in the first direction D1 of the second lid portion <NUM>. The second lid portion <NUM> is non-conductive and made of, for example, a polyamide resin.

As illustrated in <FIG> and <FIG>, the locking portion 65a is formed at an end portion in the first direction D1 of the first lid portion <NUM>. Additionally, the locking portion 65b is formed at an end portion in the first direction D1 of the second lid portion <NUM>. Specifically, the locking portions 65a and 65b are formed at ends on the sides opposite to the ends in the first direction D1 where the flanges <NUM> and <NUM> are formed in the first and second lid portions <NUM> and <NUM>. In the present embodiment, the locking portions 65a and 65b are formed by notching the edges of the base portions <NUM> and <NUM> in the first direction D1, and are configured as claw portions having elasticity in the second direction D2.

Next, the configuration of the coupling terminals <NUM> and <NUM> will be described. As illustrated in <FIG>, the coupling terminals <NUM> and <NUM> are terminals that allow coupling the busbars <NUM> to <NUM> by inserting the insertion portions 101c to 104c of the respective busbars <NUM> to <NUM> into the coupling terminals <NUM> and <NUM>. The respective insertion portions 101c and 102c of the busbars <NUM> and <NUM> are inserted into the coupling terminal <NUM>, and the respective insertion portions 103c and 104c of the busbars <NUM> and <NUM> are inserted into the coupling terminal <NUM>. The coupling terminals <NUM> and <NUM> are formed of conductive members, such as copper, and are particularly preferably materials having elasticity, such as phosphor bronze.

As illustrated in <FIG> and <FIG>, the coupling terminal <NUM> includes a first connection portion <NUM>, a second connection portion <NUM>, and a held portion <NUM>. The held portion <NUM> is a rectangular parallelepiped portion located between the first connection portion <NUM> and the second connection portion <NUM> and open in the first direction D1. As illustrated in <FIG>, the held portion <NUM> has holding surfaces 43a and 43b that are surfaces parallel to one another and facing in the second direction D2. Among the holding surfaces 43a and 43b, holding holes <NUM> are formed in the holding surface 43a, and holding holes <NUM> are formed in the holding surface 43b. Note that, in <FIG>, the holding holes <NUM> and <NUM> are illustrated by broken lines. When the housing portion <NUM> is assembled, the holding protrusions <NUM> of the first lid portion <NUM> are inserted into the holding holes <NUM>, and the holding protrusions <NUM> of the container body <NUM> are inserted into the holding holes <NUM>.

As illustrated in <FIG>, the first connection portion <NUM> includes three pairs of elastic pieces <NUM> and <NUM>. As illustrated in <FIG>, the elastic pieces <NUM> and <NUM> extend from a first edge in the first direction D1 of the held portion <NUM>, and grip the busbar <NUM> in cooperation. Each of the elastic pieces <NUM> and <NUM> has a thin plate shape and has elasticity in the direction (namely, the second direction D2) of gripping the busbar <NUM>. The elastic piece <NUM> extends from the first edge of the holding surface 43a, the elastic piece <NUM> extends from the first edge of the holding surface 43b, and the elastic piece <NUM> and the elastic piece <NUM> are paired to grip the busbar. In the present embodiment, the three pairs of elastic pieces <NUM> and <NUM> are arranged in the third direction D3 from the held portion <NUM> as the first connection portion <NUM>.

As illustrated in <FIG>, the second connection portion <NUM> includes three pairs of elastic pieces <NUM> and <NUM>. As illustrated in <FIG>, the elastic pieces <NUM> and <NUM> extend from a second edge in the first direction D1 of the held portion <NUM>, and grip the busbar <NUM> in cooperation. Each of the elastic pieces <NUM> and <NUM> has a thin plate shape and has elasticity in the direction (namely, the second direction D2) of gripping the busbar <NUM>. The elastic piece <NUM> extends from the second edge of the holding surface 43a, the elastic piece <NUM> extends from the second edge of the holding surface 43b, and the elastic piece <NUM> and the elastic piece <NUM> are paired to grip the busbar. In the present embodiment, the three pairs of elastic pieces <NUM> and <NUM> are arranged in the third direction D3 from the held portion <NUM> as the second connection portion <NUM>.

As illustrated in <FIG> and <FIG>, the coupling terminal <NUM> includes a first connection portion <NUM>, a second connection portion <NUM>, and a held portion <NUM>. In the present embodiment, the coupling terminal <NUM> has the same shape as the coupling terminal <NUM>. That is, the held portion <NUM> is a rectangular parallelepiped portion located between the first connection portion <NUM> and the second connection portion <NUM> and open in the first direction D1. As illustrated in <FIG>, the held portion <NUM> has holding surfaces 53a and 53b that are surfaces parallel to one another and facing in the second direction D2. Among the holding surfaces 53a and 53b, holding holes <NUM> are formed in the holding surface 53a, and holding holes <NUM> are formed in the holding surface 53b. Note that, in <FIG>, the holding holes <NUM> and <NUM> are illustrated by broken lines. When the housing portion <NUM> is assembled, the holding protrusions <NUM> of the second lid portion <NUM> are inserted into the holding holes <NUM>, and the holding protrusions <NUM> of the container body <NUM> are inserted into the holding holes <NUM>.

As illustrated in <FIG>, the first connection portion <NUM> includes three pairs of elastic pieces <NUM> and <NUM>. As illustrated in <FIG>, the elastic pieces <NUM> and <NUM> extend from a first edge in the first direction D1 of the held portion <NUM>, and grip the busbar <NUM> in cooperation. Each of the elastic pieces <NUM> and <NUM> has a thin plate shape and has elasticity in the direction (namely, the second direction D2) of gripping the busbar <NUM>. The elastic piece <NUM> extends from the first edge of the holding surface 53a, the elastic piece <NUM> extends from the first edge of the holding surface 53b, and the elastic piece <NUM> and the elastic piece <NUM> are paired to grip the busbar. In the present embodiment, the three pairs of elastic pieces <NUM> and <NUM> are arranged in the third direction D3 from the held portion <NUM> as the first connection portion <NUM>.

As illustrated in <FIG>, the second connection portion <NUM> includes three pairs of elastic pieces <NUM> and <NUM>. As illustrated in <FIG>, the elastic pieces <NUM> and <NUM> are configured by the elastic pieces <NUM> and <NUM> that extend from a second edge in the first direction D1 of the held portion <NUM>, and grip the busbar <NUM> in cooperation. Each of the elastic pieces <NUM> and <NUM> has a thin plate shape and has elasticity in the direction (namely, the second direction D2) of gripping the busbar <NUM>. The elastic piece <NUM> extends from the second edge of the holding surface 53a, the elastic piece <NUM> extends from the second edge of the holding surface 53b, and the elastic piece <NUM> and the elastic piece <NUM> are paired to grip the busbar. In the present embodiment, the three pairs of elastic pieces <NUM> and <NUM> are arranged in the third direction D3 from the held portion <NUM> as the second connection portion <NUM>.

Next, a procedure for assembling the noise filter <NUM> will be described with reference to <FIG> and <FIG>.

First, while the coupling terminal <NUM> is housed in the first recessed portion <NUM> of the container body <NUM>, the first lid portion <NUM> is fitted to an opening side of the first recessed portion <NUM> of the container body <NUM>. As a result, the housing space <NUM> in which the coupling terminal <NUM> is housed is formed by the inner side of the first recessed portion <NUM> and the back surface of the first lid portion <NUM>. At this time, in the coupling terminal <NUM>, the holding protrusions <NUM> of the container body <NUM> are inserted into the holding holes <NUM> of the held portion <NUM>, and the holding protrusions <NUM> of the first lid portion <NUM> are inserted into the holding holes <NUM> of the held portion <NUM>. As a result, the coupling terminal <NUM> is held in the housing space <NUM> of the housing portion <NUM> with the first connection portion <NUM> facing the opening <NUM> and the second connection portion <NUM> facing the opening <NUM> in the first direction D1. Additionally, the coupling terminal <NUM> is held in the housing space <NUM> in a state where movement in the first direction D1 is restricted by the holding protrusions <NUM> and <NUM> protruding in the second direction D2.

In the housing portion <NUM>, while the coupling terminal <NUM> is housed in the second recessed portion <NUM> of the container body <NUM>, the second lid portion <NUM> is fitted to an opening side of the second recessed portion <NUM> of the container body <NUM>. As a result, a housing space <NUM> in which the coupling terminal <NUM> is housed is formed by the inner side of the second recessed portion <NUM> and the back surface of the second lid portion <NUM>. At this time, in the coupling terminal <NUM>, the holding protrusions <NUM> of the container body <NUM> are inserted into the holding holes <NUM> of the held portion <NUM>, and the holding protrusions <NUM> of the second lid portion <NUM> are inserted into the holding holes <NUM> of the held portion <NUM>. As a result, the coupling terminal <NUM> is held in the housing space <NUM> in the housing portion <NUM> with the first connection portion <NUM> facing the opening <NUM> and the second connection portion <NUM> facing the opening <NUM> in the first direction D1. Additionally, the coupling terminal <NUM> is held in the housing space <NUM> in a state where movement in the first direction D1 is restricted by the holding protrusions <NUM> and <NUM> protruding in the second direction D2.

Then, the housing portion <NUM> is inserted into the through-hole <NUM> of the magnetic core <NUM> from the side where the locking portions 65a and 65b are formed. At this time, the locking portions 65a and 65b that have passed through the through-hole <NUM> are hooked on the edge portion of the opening <NUM> of the through-hole <NUM>, and thus the housing portion <NUM> is locked to the magnetic core <NUM>. That is, the housing portion <NUM> is reliably held within the through-hole <NUM> of the magnetic core <NUM> by the locking portions 65a and 65b. Additionally, the flanges <NUM> and <NUM> of the housing portion <NUM> butt against the edges of the opening <NUM> of the magnetic core <NUM>, and thus the insertion of the housing portion <NUM> is restricted.

Next, a procedure for coupling the busbar to the noise filter <NUM> will be described.

The insertion portion 101c of the busbar <NUM> is inserted into between the elastic pieces <NUM> and <NUM> of the first connection portion <NUM> from the opening <NUM> of the housing portion <NUM>, and the insertion portion 102c of the busbar <NUM> is inserted into between the elastic pieces <NUM> and <NUM> of the second connection portion <NUM> from the opening <NUM> of the housing portion <NUM>. In this way, the busbar <NUM> and the busbar <NUM> are coupled by the coupling terminal <NUM>, which is disposed in the through-hole <NUM> of the magnetic core <NUM>.

The insertion portion 103c of the busbar <NUM> is inserted into between the elastic pieces <NUM> and <NUM> of the first connection portion <NUM> from the opening <NUM> of the housing portion <NUM>, and the insertion portion 102c of the busbar <NUM> is inserted into between the elastic pieces <NUM> and <NUM> of the second connection portion <NUM> from the opening <NUM> of the housing portion <NUM>. In this way, the busbar <NUM> and the busbar <NUM> are coupled by the coupling terminal <NUM>, which is disposed in the through-hole <NUM> of the magnetic core <NUM>.

Here, since the insertion portions 101c to 104c of the busbars <NUM> to <NUM> are gripped by the first and second connection portions <NUM> and <NUM>, which are the elastic pieces, the insertion portions 101c to 104c are allowed to move in a direction parallel to the surfaces of the insertion portions 101c to 104c while electrical contact between the coupling terminals <NUM> and <NUM> is maintained. Similarly, the busbars <NUM> to <NUM> can be moved slightly in association with displacement of the elastic pieces in the direction (that is, the second direction D2) being gripped by the elastic pieces <NUM> to <NUM> and <NUM> to <NUM> as well. Accordingly, even when slight misalignment occurs between the busbars <NUM> and <NUM> on the side gripped by the first connection portions <NUM> and <NUM> and the busbars <NUM> and <NUM> on the side gripped by the second connection portions <NUM> and <NUM>, the busbars can be coupled with the misalignment absorbed.

In the present embodiment described above, the following effects can be provided.

(1a) The noise filter <NUM> includes the holding portion <NUM> that holds the coupling terminals <NUM> and <NUM> in the through-hole <NUM> with the first connection portions <NUM> and <NUM> facing the first opening from the inside of the through-hole <NUM> of the magnetic core <NUM> and the second connection portions <NUM> and <NUM> facing the second opening from the inside of the through-hole <NUM>.

In this way, among the two busbars, the first busbar is connected with the first connection portion <NUM> exposed from the first opening of the through-hole <NUM> of the magnetic core <NUM>, and the second busbar can be connected with the second connection portion <NUM> exposed from the second opening of the through-hole <NUM>. Thus, both busbars can be electrically coupled. Therefore, regardless of the bent shape of the busbar, the signal flowing through the first busbar is passed through the through-hole <NUM> of the magnetic core <NUM> to ensure that the signal flows to the second busbar. As a result, the noise filter <NUM> can be less likely to reduce a noise reduction effect while increasing a degree of freedom in the busbar shape in a device.

(1b) The holding portion <NUM> of the noise filter <NUM> includes the housing portion <NUM> disposed inside the through-hole <NUM>. The coupling terminals <NUM> and <NUM> are housed in the housing portion <NUM> to hold the coupling terminals <NUM> and <NUM> to the magnetic core <NUM>.

This allows the coupling terminals to be held in the through-hole while the coupling terminals <NUM> and <NUM> maintain insulation properties with the magnetic core <NUM>. Thus, while a signal is appropriately transmitted between the busbars, the noise reduction effect of the noise filter <NUM> can be less likely to be reduced.

(1c) The holding portion <NUM> is disposed inside the through-hole <NUM>. The holding portion <NUM> includes the locking portions 65a and 65b that cause the holding portion <NUM> to be locked to the magnetic core <NUM>.

This enhances a fixing force of the holding portion <NUM> with respect to the magnetic core to ensure that the coupling terminals <NUM> and <NUM> are reliably positioned in the magnetic core <NUM>. For example, even when an external force is applied to the coupling terminals <NUM> and <NUM> via the busbars, it can be suppressed that the coupling terminals <NUM> and <NUM> are pulled out of the through-hole <NUM> of the magnetic core <NUM>, and reduction in noise reduction effect of the noise filter <NUM> can be suppressed.

(1d) In the first embodiment described above, the coupling terminals <NUM> and <NUM> have the holding holes formed in the held portions <NUM> and <NUM>, and the housing portion <NUM> has the holding protrusions inserted into the holding holes. Instead of this, the coupling terminals <NUM> and <NUM> may have holding protrusions on the held portions <NUM> and <NUM>, and the housing portion <NUM> may have holding holes.

(1e) In the first embodiment described above, the holding portion <NUM> includes the locking portions 65a and 65b. Instead of this, the holding portion <NUM> need not include the locking portions 65a and 65b. Additionally, the holding portion <NUM> may include one locking portion instead of including the two locking portions 65a and 65b.

In the second embodiment, the configuration different from the first embodiment will be mainly described. Note that in the second embodiment, the same reference numerals are assigned to the same portions as those of the first embodiment, and the description thereof will not be repeated.

In the present embodiment, as illustrated in <FIG>, the noise filter <NUM> includes a case <NUM> that houses the magnetic core <NUM>. Additionally, the holding portion holding the coupling terminal is integrally formed with the case <NUM>. <FIG> is a cross-sectional view of the noise filter <NUM> according to the present embodiment in a surface parallel to the first direction D1. <FIG> is a cross-sectional view of the noise filter <NUM> according to the present embodiment in a surface parallel to the second direction D2.

As illustrated in <FIG> and <FIG>, the case <NUM> includes a case body <NUM> and a lid portion <NUM>. The case <NUM> is made of a non-conductive resin, for example, a polyamide resin that can be used as the material. The case body <NUM> includes an outer tubular portion <NUM>, a through-tubular portion <NUM>, a bottom portion <NUM>, and a partition wall <NUM>. The outer tubular portion <NUM> is a tubular portion extending in the first direction D1 from a first surface of the bottom portion <NUM>. An end on the side opposite to the bottom portion <NUM> of the outer tubular portion <NUM> is open. The through-tubular portion <NUM> is a tubular portion that extends in the same direction as the extending direction of the outer tubular portion <NUM> from the first surface of the bottom portion <NUM> inside the outer tubular portion <NUM>. Specifically, the outer diameter dimension of the through-tubular portion <NUM> is smaller than the outer diameter dimension of the outer tubular portion <NUM>. As a result, a housing space <NUM> housing the magnetic core <NUM> is formed between an inner peripheral surface of the outer tubular portion <NUM> and an outer peripheral surface of the through-tubular portion <NUM>.

As illustrated in <FIG>, the partition wall <NUM> is a plate-like portion that extends so as to partition the inside of the through-tubular portion <NUM>. As a result, two terminal housing spaces separated by the partition wall <NUM> are formed inside the through-tubular portion <NUM>.

The lid portion <NUM> is a ring-shaped member having an opening in the center. The lid portion <NUM> is attached to the case body <NUM> so as to cover an opening of the housing space <NUM> formed between the outer tubular portion <NUM> and the through-tubular portion <NUM> at the end on the side opposite to the bottom portion <NUM> of the case body <NUM>.

Holding portions <NUM> are integrally formed with the case <NUM>. In the present embodiment, the holding portion <NUM> is provided in each of the two terminal housing spaces separated by the partition wall <NUM> inside the through-tubular portion <NUM>. Specifically, the holding portion <NUM> includes an extending piece <NUM> and locking pieces <NUM>. The extending piece <NUM> is a piece-shaped portion extending inward from an inner peripheral surface of the through-tubular portion <NUM>. The locking piece <NUM> is a portion extending from the extending piece <NUM> in the first direction D1, and having a distal end with a claw shape. Specifically, the locking piece <NUM> protrudes from a position on the inner peripheral surface side by a specified dimension in the third direction D3 from a distal end of the extending piece <NUM>. In the holding portion <NUM> having the configuration described above, the held portions <NUM> and <NUM> of the coupling terminals <NUM> and <NUM> can be sandwiched between the distal end of the locking piece <NUM> and the distal end of the extending piece <NUM>.

In the case <NUM> having the configuration described above, the magnetic core <NUM> is housed in the housing space <NUM> in the case <NUM> with the through-tubular portion <NUM> passing through the through-hole <NUM>. In each of the two terminal housing spaces defined by the partition wall <NUM> inside the through-tubular portion <NUM>, the coupling terminal <NUM> or <NUM> is housed to be held by the holding portion <NUM>. In the present embodiment as well, the coupling terminals <NUM> and <NUM> are held to the magnetic core <NUM> by the holding portions <NUM> with the respective connection portions <NUM>, <NUM>, <NUM>, and <NUM> facing in the first direction D1. In the present embodiment, the through-tubular portion <NUM> is an example of a through-portion.

(2a) In the present embodiment described above, the noise filter <NUM> includes the case <NUM> housing the magnetic core <NUM> and made of a non-conductive resin. The case <NUM> includes the through-tubular portion <NUM> having the tubular shape. The case <NUM> houses the magnetic core <NUM> in a state where the through-tubular portion <NUM> passes through the through-hole <NUM> of the magnetic core <NUM>. Each of the coupling terminals <NUM> and <NUM> is disposed inside the through-tubular portion <NUM>.

As a result, in the noise filter <NUM> provided with the case <NUM> as well, the same effects as those of the first embodiment can be obtained.

(2b) The holding portion <NUM> is disposed inside the through-hole <NUM> of the magnetic core <NUM> and is integrally formed with the case <NUM>.

As a result, in the noise filter provided with the case <NUM> as well, an increase in the number of components can be suppressed while the same effects as those of the first embodiment are provided.

(2c) In the second embodiment described above, the holding portion <NUM> integrally formed with the case <NUM> includes the extending piece <NUM> and the locking pieces <NUM>. Instead of this, holding protrusions to be inserted into the holding holes provided in the held portions of the coupling terminals <NUM> and <NUM> may be formed as the holding portions <NUM> on the inner peripheral surface of the through-tubular portion <NUM> in the case <NUM>. In this case, the coupling terminals <NUM> and <NUM> disposed inside the through-tubular portion <NUM> are held in a state where the holding protrusions included in holding members are inserted into the holding holes formed in the held portions.

(2d) The holding portions <NUM> hold the coupling terminals <NUM> and <NUM> inside the through-hole <NUM> of the magnetic core <NUM>. Instead of this, the holding portions <NUM> may be integrally formed with the case <NUM> and hold the coupling terminals <NUM> and <NUM> from the outside of the through-hole <NUM>.

The technique disclosed in this specification is not limited to the above-described embodiments, can be modified to various configurations without departing from the gist of the present invention as defined in the claims, and, for example, can be modified as follows.

(3a) In the respective embodiments described above, the two coupling terminals <NUM> and <NUM> are held by the holding portions <NUM> in the through-hole <NUM> of the magnetic core <NUM>. Instead of this, one coupling terminal may be held by the holding portion <NUM> in the through-hole <NUM> of the magnetic core <NUM>.

Claim 1:
A noise filter (<NUM>), comprising:
a non-divided type magnetic core (<NUM>) in which a through-hole having a first opening (<NUM>) and a second opening (<NUM>) at respective ends of the through-hole is formed;
characterized by a conductive coupling terminal (<NUM>, <NUM>) including a first connection portion (<NUM>, <NUM>) and a second connection portion (<NUM>, <NUM>) at respective ends of the conductive coupling terminal, the first connection portion and the second connection portion being connectable to busbars (<NUM>, <NUM>),
the conductive coupling terminal being disposed inside the through-hole; and
a holding portion (<NUM>) that holds the coupling terminal disposed inside the through-hole, wherein
the coupling terminal is held to the magnetic core by the holding portion in a state where the first connection portion faces the first opening from inside of the through-hole and the second connection portion faces the second opening from inside of the through-hole.