Noise filter

Abstract

We aim to reduce the number of parts. [Solution] Noise filter A comprises a core 10 containing a magnetic material 30, an edgewise coil 24 surrounding the outer surface of the core 10, and a bolt 20 as a fixing part provided on the core 10, the bolt 20 being directly fixed to the object P to be fixed. Noise filter A does not require a case to house the core 10 and the edgewise coil 24. Since noise filter A can be directly fixed to the object P by the bolt 20 without the intermediary of a case, the number of parts can be reduced compared to those that use a case.

Description

Technical Field

[0001] The present disclosure relates to a noise filter.

Background Art

[0002] Patent Document 1 discloses a box-shaped noise filter in which a bobbin having a core accommodated therein and a coil wound around an outer periphery thereof is accommodated in a metal case. The flange portion of the bobbin is fixed to the metal case by a screw.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the above box-shaped noise filter is attached to an automobile body, the metal case must be fixed to the body using bolts, nuts, etc. Therefore, there is a problem of a large number of parts.

[0005] The noise filter of the present disclosure has been completed based on the above circumstances, and aims to reduce the number of parts.

Means for Solving the Problems

[0006] The noise filter of the present disclosure includes a core containing a magnetic material, a coil surrounding an outer peripheral surface of the core, and a fixing portion provided on the core, and the fixing portion is directly fixed to a fixing object.

Effects of the Invention

[0007] According to this disclosure, it is possible to reduce the number of parts. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view of the noise filter of Example 1. [Figure 2] Figure 2 is a plan view of the noise filter. [Figure 3] Figure 3 is a cross-sectional view of the noise filter fixed to the object. [Figure 4] Figure 4 is a front view showing the noise filter of Example 2 fixed to the mounting target. [Figure 5] Figure 5 is a front view showing the noise filter of Example 3 fixed to the mounting target. [Modes for carrying out the invention]

[0009] [Description of Embodiments in this Disclosure] First, embodiments of this disclosure will be listed and described. Any combination of the following embodiments, insofar as they do not contradict each other, is also included as a form for carrying out the invention. The noise filter in this disclosure is (1) The noise filter comprises a core containing a magnetic material, a coil surrounding the outer surface of the core, and a fixing part provided on the core, wherein the fixing part is directly fixed to the object to be fixed. With this configuration, the noise filter does not have a case to house the core and coil. The noise filter can be directly fixed to the object to be fixed by bolts without the need for a case, thus reducing the number of parts.

[0010] (2) In (1), it is preferable that the fixing portion is conductive and in electrically conductive contact with the magnetic material, and that the fixing portion is electrically connectable to the ground portion of the object to be fixed. With this configuration, the core and the ground portion can be grounded via the fixing portion.

[0011] (3) In (1) or (2), the fixing portion preferably includes a male threaded portion that is screwed into the nut of the object to be fixed. With this configuration, the fixing portion can be fixed to the object to be fixed by the simple operation of screwing the male threaded portion into the nut.

[0012] In (4)(3), the core includes a housing member having a housing space and the magnetic material housed within the housing member, and the fixing portion is preferably a bolt having a male threaded portion and a large-diameter portion formed at one end of the male threaded portion, wherein the male threaded portion penetrates the bottom wall of the housing member so as to be rotatable relative to it and protrudes to the outside of the housing member, and the large-diameter portion is preferably held in a state sandwiched between the bottom wall and the magnetic material within the housing space. With this configuration, since the fixing portion is rotatable relative to the housing member, the core can be fixed to the object to be fixed in a desired orientation.

[0013] (5) In (1) or (2), the fixing portion protrudes from the surface of the core facing the object to be fixed and is fixed in a state embedded in the object to be fixed, and the coil is preferably an edgewise coil with its axis oriented parallel to the protruding direction of the fixing portion. With this configuration, the protruding dimension of the noise filter in the direction of protrusion from the object to be fixed can be kept small.

[0014] [Details of the embodiments of this disclosure] [Example 1] A noise filter A of Embodiment 1, embodying this disclosure, will be described with reference to Figures 1 to 3. The present invention is not limited to these examples, but is shown in the claims, and all modifications within the meaning and scope of equivalence to the claims are included. In Embodiment 1, the front-to-back direction is defined as direction F in Figures 1 and 2. The up-and-down direction is defined as direction H in Figures 1 and 3. The left-to-right direction is defined as direction L in Figures 1 to 3. The up-and-down direction and the axial direction of the noise filter A are used synonymously.

[0015] The noise filter A of the first embodiment is used by being fixed to a plate-shaped fixing object P such as an automobile body. As shown in FIG. 3, the fixing object P is a horizontally plate-shaped metal member. The fixing object P has a function as a grounding portion E for grounding. An attachment hole H penetrating the fixing object P in the vertical direction is formed in the fixing object P. A nut N having an axis directed in the vertical direction is fixed to the lower surface of the fixing object P concentrically with the attachment hole H by welding M.

[0016] The noise filter A includes a core 10, a bolt 20, and an edgewise coil 24. The core 10 has a housing member 11 and a magnetic body 30 such as a ferrite core. The housing member 11 is a single component having a shaft portion 12, an upper flange portion 13, and a lower flange portion 14. The housing member 11 is made of a metal magnetic material. It may also be made of a non-magnetic material. In a plan view of the core 10 and the edgewise coil 24 seen from above, the outer peripheral edge of the shaft portion 12 forms a square. A plan view is synonymous with an axial direction view in which the core 10 and the edgewise coil 24 are viewed in the axial direction. An accommodation space 15 having a square shape in the axial direction view is formed inside the shaft portion 12. The upper end of the accommodation space 15 opens to the upper surface of the shaft portion 12. The lower end of the accommodation space 15 is closed by a bottom wall portion 16. A circular through hole 17 is formed in the bottom wall portion 16 of the shaft portion 12.

[0017] The upper flange portion 13 is formed at the upper end portion of the shaft portion 12. The shape of the upper flange portion 13 in the axial direction view is a square. The upper surface of the upper flange portion 13 is flush and continuous with the upper surface of the shaft portion 12. In the axial direction view, the length of one side of the upper flange portion 13 is longer than the length of one side of the shaft portion 12. The lower flange portion 14 is formed at the lower end portion of the shaft portion 12. The shape of the lower flange portion 14 in the axial direction view is a square. In the axial direction view, the length of one side of the lower flange portion 14 is longer than the length of one side of the upper flange portion 13. The lower surface of the lower flange portion 14 is flush and continuous with the lower surface of the bottom wall portion 16 of the shaft portion 12.

[0018] The bolt 20 is a single component having a male screw portion 21 and a large-diameter portion 22 formed at the upper end of the male screw portion 21. The bolt 20 is made of a conductive material such as metal. The planar shape of the large-diameter portion 22 forms a circle with an outer diameter dimension larger than that of the male screw portion 21. At the central portion on the upper surface of the large-diameter portion 22, a fitting recess 23 for fitting a hexagonal wrench (not shown) or the like as a tightening tool is formed. The bolt 20 is inserted into the accommodation space 15 from above the accommodation member 11, with the male screw portion 21 penetrating through the through-hole 17 and the large-diameter portion 22 placed on the upper surface of the bottom wall portion 16. The male screw portion 21 is rotatable within the through-hole 17.

[0019] The magnetic body 30 is a prismatic single component made of a metallic magnetic material. The planar shape of the magnetic body 30 is the same square shape as the accommodation space 15. The magnetic body 30 is accommodated within the accommodation space 15. The bottom surface of the magnetic body 30 is placed on the upper surface of the large-diameter portion 22 of the bolt 20. The magnetic body 30 accommodated within the accommodation space 15 is held in a state where detachment from the accommodation space 15 is restricted by welding M or the like. The large-diameter portion 22 of the bolt 20 is held in a state of being sandwiched vertically between the bottom wall portion 16 and the magnetic body 30.

[0020] The edgewise coil 24 is a single component consisting of a single flat rectangular wire 25. The cross-sectional shape of the flat rectangular wire 25 is a wire forming a rectangle with a relatively large ratio of the horizontal long side to the vertical short side. The flat rectangular wire 25 is a member in which a conductor (not shown) made of a conductive material such as copper, aluminum, or carbon nanotube is surrounded by an insulating coating (not shown). The edgewise coil 24 is formed by bending the flat rectangular wire 25 so that the short side (plate thickness surface) is bent in a plan view. Since the short side in the cross-section of the flat rectangular wire 25 is oriented in the axial direction (vertical direction), the dimension in the axial direction is kept small.

[0021] The edgewise coil 24 has a first coil section 26 and a second coil section 27 and is mounted on the lower flange section 14. The first coil section 26 and the second coil section 27 are connected by folding back at the lower end of the edgewise coil 24. The first coil section 26 is a portion that has been bent to form a square shape in plan view and is arranged to surround the shaft section 12. The upper surface of the first coil section 26 is pressed down from above by the upper flange section 13. The second coil section 27 is a portion that has been bent to form a square shape in plan view and is arranged to surround the first coil section 26. A first connection terminal section 28 extends horizontally from the upper end of the first coil section 26. A second connection terminal section 29 extends horizontally from the upper end of the second coil section 27.

[0022] The procedure for fixing the noise filter A to the object P is described below. With the edgewise coil 24 assembled to the housing member 11 and the magnetic material 30 removed from the housing space 15, the bolt 20 is inserted into the housing space 15 and the male threaded portion 21 is passed through the through hole 17. Next, the lower end of the male threaded portion 21 is passed through the mounting hole H and lightly screwed into the nut N, and the bottom wall portion 16 of the housing member 11 is placed on the upper surface of the object P. Then, a tool such as a screwdriver (not shown) is fitted into the fitting recess 23 of the bolt 20, and the bolt 20 is rotated to screw the male threaded portion 21 into the nut N.

[0023] The male threaded portion 21 is tightened onto the nut N until the large diameter portion 22 abuts against the upper surface of the bottom wall portion 16 and the bottom wall portion 16 is clamped between the large diameter portion 22 and the object to be fixed P. Before tightening the male threaded portion 21 onto the nut N, the orientation of the housing member 11 can be changed to appropriately set the extension direction of the first connection terminal portion 28 and the second connection terminal portion 29 of the edgewise coil 24. The frictional resistance between the bottom surface 18 of the housing member 11 and the upper surface of the object to be fixed P fixes the core 10 in a state where its rotation is restricted relative to the object to be fixed P. As a result, the housing member 11 is fixed to the object to be fixed P. After fixing the housing member 11 to the object to be fixed P, the magnetic body 30 is housed in the housing space 15, and the large diameter portion 22 of the bolt 20 is clamped between the bottom surface of the magnetic body 30 and the bottom wall portion 16. The magnetic body 30 is grounded to the object to be fixed P via the bolt 20. The magnetic material 30 is fixed to the housing member 11 by welding M or the like. Thus, the noise filter A is fixed to the object P.

[0024] The noise filter A of this embodiment 1 comprises a core 10 containing a magnetic material 30, an edgewise coil 24 surrounding the outer surface of the core 10, and a bolt 20 provided on the core 10. The bolt 20 is directly fixed to the object P to be fixed. With this configuration, the noise filter A does not have a case to house the core 10 and the coil. Since the noise filter A can be directly fixed to the object P by the bolt 20 without the intermediary of a case, the number of parts can be reduced compared to those that use a case.

[0025] The bolt 20 is conductive and is in electrically conductive contact with the magnetic material 30. The bolt 20 is electrically connected to the grounding portion E of the object P to be fixed. With this configuration, the core 10 and the grounding portion E can be grounded via the bolt 20. The bolt 20 includes a male threaded portion 21 that is screwed into the nut N of the object P to be fixed. With this configuration, the bolt 20 can be fixed to the object P by the simple operation of screwing the male threaded portion 21 into the nut N.

[0026] The core 10 includes a housing member 11 having a housing space 15 and a magnetic material 30 housed within the housing member 11. The bolt 20 has a male threaded portion 21 and a large-diameter portion 22 formed at one end of the male threaded portion 21. The male threaded portion 21 penetrates the bottom wall portion 16 of the housing member 11 so as to be rotatable relative to it and protrudes to the outside of the housing member 11. The large-diameter portion 22 is held within the housing space 15, sandwiched between the bottom wall portion 16 and the magnetic material 30. With this configuration, since the bolt 20 is rotatable relative to the housing member 11, the core 10 can be fixed to the object P in a desired orientation.

[0027] The bolt 20 protrudes from the bottom surface 18 of the housing member 11 (the surface of the core 10 facing the object to be fixed P) and is fixed in an embedded state relative to the object to be fixed P. The coil is an edgewise coil 24 with its axis oriented parallel to the protruding direction of the bolt 20. Because the edgewise coil 24 has a small dimension in the axial direction (vertical direction), the protruding dimension of the noise filter A in the direction of protrusion from the object to be fixed P (upward) can be kept small.

[0028] [Example 2] A noise filter B of Embodiment 2, which embodies the present disclosure, will be described with reference to Figure 4. The noise filter B of Embodiment 2 comprises a core 40, a bolt 42 as a fixing part, and an edgewise coil 24. The core 40 is a single component made of a magnetic material. The core 40 has a shaft portion 12, an upper flange portion 13, and a lower flange portion 14. The shape of the core 40 is the same as that of the housing member 11 of Embodiment 1, except that the shaft portion 12 does not have a housing space 15 and a through hole 17.

[0029] The bolt 42 has a male threaded portion 43. The bolt 42 is integrated with the core 40 in such a way that the male threaded portion 43 protrudes downward from the bottom surface 44 of the core 40. As a means of integrating the bolt 42 with the core 40, the bolt 42 may be molded integrally with the core 40, or the core 40 and the bolt 42 may be molded as separate parts and the upper end of the bolt 42 may be fixed to the bottom surface 44 of the core 40 by welding or the like.

[0030] The edgewise coil 24 is the same component as in Example 1. The edgewise coil 24 is attached to the core 40 in the same configuration as in Example 1. The object to be fixed P is also a component of the same configuration as in Example 1. The object to be fixed P is provided with a mounting hole H and a nut N, as in Example 1.

[0031] When fixing the noise filter B to the object P, the male threaded portion 43 is passed through the mounting hole H of the object P and lightly fitted into the nut N. From this position, the entire noise filter B is rotated while the male threaded portion 43 is screwed into the nut N. After the bottom surface 44 of the core 40 comes into contact with the top surface of the object P, the male threaded portion 43 is tightened into the nut N, causing the bottom surface 44 of the core 40 to be pressed tightly against the top surface of the object P. The noise filter B is fixed to the object P by the frictional resistance between the bottom surface 44 of the core 40 and the top surface of the object P.

[0032] The noise filter B of this embodiment 2 comprises a core 40 containing a magnetic material, an edgewise coil 24 surrounding the outer surface of the core 40, and a bolt 42 provided on the core 40. The bolt 42 is directly fixed to the object P to be fixed. Since a case to house the core 40 and coil is not required, the number of parts can be reduced. The noise filter B, including the bolt 42, can be fixed to the object P by a simple operation of screwing the male threaded portion 43 into a nut N.

[0033] The bolt 42 is conductive and can conduct electricity with the core 40. The bolt 42 is electrically connected to the grounding portion E of the object P to be fixed. With this configuration, the core 40 and the grounding portion E can be grounded via the bolt 42.

[0034] [Example 3] A noise filter C of Embodiment 3, which embodies the present disclosure, will be described with reference to Figure 5. The noise filter C of Embodiment 3 comprises a core 50, a female screw hole 51 as a fixing part, and an edgewise coil 24. The core 50 is a single component made of a magnetic material. The core 50 has a shaft portion 12, an upper flange portion 13, and a lower flange portion 14. The external shape of the core 50 is the same as that of the housing member 11 of Embodiment 1, except that the shaft portion 12 does not have a housing space 15 and a through hole 17. The edgewise coil 24 is the same component as in Embodiment 1. The edgewise coil 24 is attached to the core 50 in the same form as in Embodiment 1.

[0035] The female screw hole 51 is formed with its axis oriented vertically, drilling upward from the bottom surface 52 of the core 50 into the shaft portion 12. It has a stud bolt S. Unlike Embodiments 1 and 2, the object to be fixed P does not have a mounting hole H and a nut N. The stud bolt S is provided on the upper surface of the object to be fixed P in a form that protrudes upward with its axis oriented vertically. The stud bolt S is manufactured as a separate part from the object to be fixed P and is fixed to the upper surface of the object to be fixed P by welding or the like.

[0036] When fixing the noise filter C to the object P, the female screw hole 51 is shallowly fitted onto the upper end of the stud bolt S, and from that state, the entire noise filter C is rotated while the female screw hole 51 is screwed onto the stud bolt S. After the bottom surface 52 of the core 50 comes into contact with the top surface of the object P, the female screw hole 51 is tightened onto the stud bolt S, so that the bottom surface 52 of the core 50 is pressed tightly against the top surface of the object P. The noise filter C is fixed to the object P by the frictional resistance between the bottom surface 52 of the core 50 and the top surface of the object P.

[0037] The noise filter C of this embodiment 3 comprises a core 50 containing a magnetic material, an edgewise coil 24 surrounding the outer surface of the core 50, and a female screw hole 51 provided in the core 50. The female screw hole 51 is directly fixed to the object P to be fixed. Since a case to house the core 50 and coil is not required, the number of parts can be reduced. The noise filter C can be fixed to the object P by a simple operation of screwing the female screw hole 51 onto a stud bolt S.

[0038] [Other examples] The present invention is not limited to the embodiments described above and in the drawings, but is shown in the claims. The present invention includes the meaning of equivalents to the claims and all modifications within the claims, and also includes the following embodiments. In Examples 1 to 3, the bolt (fixing part) may be one that does not have the function of connecting the core and the grounding part to the earth. In Examples 1 to 3, the fixing part may be a clip that is fixed by locking it to the object to be fixed with an elastic locking piece. In Examples 1 to 3, the containment member may be made of a non-metallic magnetic material or a non-magnetic material. In Examples 1 to 3, the magnetic material is not limited to metal; it may also be a synthetic resin or rubber mixed with magnetic powder. In Examples 1-3, the coil is not limited to an edgewise coil; it may also be made by spirally winding wires with a circular or square cross-section. The core of Example 1 may be a single component as in Examples 2 and 3. The magnetic material in Example 1 may be cylindrical or in a shape other than a prismatic shape. The cores of Examples 2 and 3 may be configured in a form in which a magnetic material is housed in a housing member, as in Example 1. In Example 3, instead of forming a female screw hole in the core, a nut may be fixed to the bottom surface of the core as a fixing part. The object to which the noise filter is fixed (such as a car body) may or may not be conductive. • The object to be fixed is not limited to metal; it may also be made of synthetic resin. The bolt material is not limited to metal; it can also be a combination of metal and conductive carbon, or even a non-conductive material. The object to be fixed is not limited to the car body; it may also be a harness protector, etc. [Explanation of Symbols]

[0039] A... Noise filter B... Noise filter C... Noise filter E…Grounding part H...Mounting hole M...Welding N...nut P... Fixed object S... Stud bolt 10... Cores 11…Housing component 12... Shaft 13…Upper flange section 14…Lower flange section 15…Containment space 16...Bottom wall 17…Through hole 18…Bottom surface of the housing member (the surface facing the object to be fixed in the core) 20... Bolt (fixing part) 21...Male screw part 22...Large diameter section 23…Matching recess 24… Edgewise coil (coil) 25... Flat-angled line 26...First coil section 27...Second coil section 28...First connection terminal section 29...Second connection terminal section 30...Magnetic material 40...cores 42... Bolt (fixing part) 43...Male screw part 44...Bottom 50...cores 51...Female screw hole (fixed part) 52...Bottom

Claims

1. A core containing a magnetic material, A coil surrounding the outer surface of the core, The core comprises a fixing portion, The aforementioned fixing part is a noise filter that is directly fixed to the object to be fixed.

2. The aforementioned fixing portion is conductive and is in contact with the magnetic material in a manner that allows for electrical communication. The noise filter according to claim 1, wherein the fixing portion can be electrically connected to the ground portion of the object to be fixed.

3. The noise filter according to claim 1 or claim 2, wherein the fixing portion includes a male threaded portion that is screwed into a nut of the object to be fixed.

4. The core includes a housing member having a housing space and the magnetic material housed within the housing member. The fixing portion is a bolt having a male threaded portion and a large-diameter portion formed at one end of the male threaded portion. The male screw portion penetrates the bottom wall of the housing member so as to be rotatable relative to it and protrudes to the outside of the housing member. The noise filter according to claim 3, wherein the large-diameter portion is held in a state sandwiched between the bottom wall portion and the magnetic material within the housing space.

5. The fixing portion is configured to protrude from the surface of the core facing the object to be fixed and to be fixed in a state where it is embedded in the object to be fixed. The noise filter according to claim 1 or claim 2, wherein the coil is an edgewise coil with its axis oriented parallel to the protruding direction of the fixed portion.

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