JP6308432B2 - Noise filter - Google Patents

Description

  The present invention relates to a noise filter.

  Patent Document 1 discloses a noise filter in which a ferrite core surrounding a conductive path is accommodated in a case. The ferrite core is configured by combining a pair of core components that form a semi-cylindrical shape. The case is made of synthetic resin, and is configured by combining a pair of case components connected by hinges. The case structure is formed with an elastic pressing piece in which a part thereof protrudes toward the outer peripheral surface of the ferrite core. When the case structure is combined, the elastic pressing piece becomes the outer peripheral surface of the core structural body. Is elastically pressed toward the center side. The pair of core components are held in close contact by the pressing action of the elastic pressing pieces, and the reliability of the noise removal function is enhanced.

JP2013-110170A

  In the region of the case where the elastic pressing piece is formed, a slit is formed between the case and the elastic pressing piece in order to allow the elastic pressing piece to elastically deform. Since this slit has a form in which the case is partially removed, the structure of the mold for molding the case becomes complicated. This means that the manufacturing cost of the case becomes high, and improvement is desired.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to inexpensively manufacture a case including means for holding a split type ferrite core in a combined state.

The noise filter of the present invention is
A ferrite core having a cylindrical shape in which the first and second core components divided in the circumferential direction are combined;
A case made of synthetic resin for housing the ferrite core ;
A holder that is fitted on a part of the case in the circumferential direction ;
The case is
A receiving portion for contacting the outer peripheral surface of the first core component;
An elastic pressing piece that extends in a cantilevered manner from an end edge in the circumferential direction of the receiving portion and is elastically deflectable in the radial direction, and elastically presses the outer periphery of the second core component toward the receiving portion. And configured with
The holder is
A highly rigid portion capable of contacting the outer periphery of the elastic pressing piece;
The high-rigidity portion includes a low-rigidity portion that extends in a cantilevered manner from an edge portion in the circumferential direction of the high-rigidity portion and can be elastically bent in the radial direction and elastically abuts against the outer periphery of the receiving portion. It has the characteristics in the place.

The elastic pressing piece, which is a means for holding the first core constituent body and the second core constituent body in a combined state, has a form extending in a cantilevered manner from the end edge portion in the circumferential direction of the receiving portion. , There is no need to form a partially removed slit. Therefore, the structure of the mold for molding the case can be simplified, and the manufacturing cost of the case can be reduced. Moreover, since it can control that an elastic press piece expands and deforms to radial direction outward, a 1st core structure and a 2nd core structure can be hold | maintained reliably.

Front view showing a state where the noise filter of Reference Example 1 is attached to the conductive path Partial cutaway right side view showing the noise filter attached to the conductive path XX sectional view of FIG. Front view of the case alone Sectional drawing which cut and showed the state which attached the noise filter of the reference example 1 to the conductive path at right angles to the axis Front view of the case alone Right side view of the case alone Front view of holder Left side view of holder

(1) In the noise filter of the present invention, a stopper capable of restricting displacement of the first core structural body housed in the receiving portion in the axial direction is formed at an end portion in the axial direction of the receiving portion. It may be.
According to this structure, it can prevent that a 1st core structure body moves to an axial direction, and detach | leaves from a receiving part.

(2) In the noise filter of the present invention, a restriction capable of restricting displacement of the second core structural body pressed by the elastic pressing piece in the axial direction at an end portion in the axial direction of the elastic pressing piece. A part may be formed.
According to this structure, it can prevent that a 2nd core structure body moves to an axial direction, and detach | leaves from an elastic press piece.

(3) In the noise filter of the present invention, the first core constituent body and the second core constituent body accommodated in the case are axially disposed at one end portion in the axial direction of the receiving portion and the elastic pressing piece. A case-side stopper capable of restricting displacement in the direction is formed, and at the other end in the axial direction of the high-rigidity portion and the low-rigidity portion, the first core structure housed in the case; A holder-side stopper capable of restricting displacement of the second core constituent body in the axial direction to the side opposite to the case-side stopper may be formed.
According to this structure, the operation | work at the time of accommodating a core structure in a case becomes easy. And in the state which assembled | attached the case and the holder, it can hold | maintain in the accommodation state by pinching | interposing the ferrite core in a case between a case side stopper and a holder side stopper.

< Reference Example 1 >
Reference Example 1 of the present invention will be described below with reference to FIGS. In the first reference example , for the front-rear direction, the left side in FIG. 2 is defined as the front. For the left-right direction and the up-down direction, directions appearing in FIGS. 1, 3, and 4 are defined as right, left, upper, and lower as they are.

As shown in FIGS. 1 and 3, the noise filter Fa of the first reference example is attached so as to surround a conductive path 30 such as a wire harness or various electric wires, and removes noise from the conductive path 30. . The noise filter Fa includes a ferrite core 10 and a case 20. The ferrite core 10 is configured by combining a pair of symmetrical first and second core constituting bodies 11A and 11B having a semi-cylindrical shape into a cylindrical shape. The inner diameter of the ferrite core 10 is set to be slightly larger than the outer diameter of the conductive path 30. In order to sufficiently exhibit the noise removal function by the ferrite core 10, it is preferable that the facing surfaces 12A and 12B opposed to each other in the circumferential direction of the core structural bodies 11A and 11B are in close contact with each other. A case 20 to be described later is provided with means for bringing the core components 11A and 11B into close contact with each other.

  The case 20 is made of a synthetic resin and is a single part having a vertically symmetrical shape. As shown in FIG. 4, the case 20 includes a semicylindrical receiving portion 21 disposed in the left half region of the case 20 and a pair of vertically symmetrical elastic pressing pieces 22 thinner than the receiving portion 21. It is configured. The formation area of the elastic pressing piece 22 in the front-rear direction (axial direction) is the same range as the formation area of the receiving portion 21. The region where the receiving portion 21 is formed in the circumferential direction is a range over a half circumference (ie, 180 °). The curvature radius of the inner peripheral surface of the receiving portion 21 is substantially the same as the curvature radius of the outer peripheral surface of the ferrite core 10 (core constituent bodies 11A and 11B). 11 A of 1st core structures are attached to the receiving part 21 in the state closely_contact | adhered to the inner peripheral surface of the receiving part 21 in the outer peripheral surface.

  The pair of elastic pressing pieces 22 are in a form that cantilevered obliquely rightward along the circumferential direction from both edge portions in the circumferential direction of the receiving portion 21. The formation area of one elastic pressing piece 22 in the circumferential direction is a range smaller than ¼ circumference (90 °). Therefore, between the extended end edge portions 23 of the upper and lower elastic pressing pieces 22, a circumferential surface opening 24 is formed that extends along the front-rear direction and is open to both front-rear ends of the case 20.

  The inner peripheral surface of the base end edge portion in the circumferential direction of the elastic pressing piece 22 and the inner peripheral surface of both end edge portions in the circumferential direction of the receiving portion 21 are smoothly continuous (that is, the curvature changes greatly) , In series so that there is no step. In a state before the ferrite core 10 is attached to the case 20, the radius of curvature of the inner peripheral surface of the elastic pressing piece 22 is set to be slightly smaller than the radius of curvature of the outer peripheral surfaces of the core constituting bodies 11A and 11B. Further, the radial dimension from the center of the arc of the receiving portion 21 to the inner peripheral surface of the extending end edge portion 23 of the elastic pressing piece 22 is the inner peripheral surface of the receiving portion 21 (the outer periphery of the core components 11A and 11B). Surface) is set to a size smaller than the radius of curvature.

  Since the thickness of the receiving portion 21 is set to be relatively large, the receiving portion 21 hardly deforms to change the curvature. On the other hand, since the thickness of the elastic pressing piece 22 is set to be smaller than that of the receiving portion 21, the elastic pressing piece 22 is displaced in the radial direction with the base end edge portion serving as a substantial fulcrum (that is, to expand the diameter). B) It can be elastically bent. As the elastic pressing piece 22 is elastically deformed, the extended end edge portion 23 of the elastic pressing piece 22 is displaced outward in the radial direction. 20), an inward biasing force in the abrasive direction that is displaced toward the center side is accumulated.

  A stopper 25 is formed at the front end portion (one end portion in the axial direction) of the receiving portion 21. The stopper 25 has a form extending in a plate shape from the inner periphery of the receiving portion 21 to the inside (the center side of the case 20). The formation region of the stopper 25 in the circumferential direction is the same range as the formation region of the receiving portion 21. The front view shape of the inner peripheral edge 26 (extension end edge) of the stopper 25 is a semicircular shape concentric with the receiving portion 21. The radius of curvature of the inner peripheral edge 26 of the stopper 25 is set to be the same as or slightly smaller than the radius of curvature of the outer peripheral surface of the conductive path 30.

  The length from the rear surface of the stopper 25 to the rear end of the receiving portion 21 is set to be the same as or slightly smaller than the axial length of the ferrite core 10 (core structural bodies 11A and 11B). A substantially semicircular region that is not covered by the stopper 25 in the front surface of the case 20 is a substantially semicircular front opening 27 </ b> F that communicates the inside and outside of the case 20. The rear surface of the case 20 is opened over the entire area, and is a substantially circular rear surface opening portion 27 </ b> R that communicates the inside and outside of the case 20. Since the case 20 can be formed by a mold (not shown) that is opened in the front-rear direction, a slide mold is unnecessary.

  The extending end edge portion 23 of the elastic pressing piece 22 is formed with a restricting portion 28 that protrudes inward in the radial direction from the front end edge (the end edge on the same side as the stopper 25 in the front-rear direction). The rear surface of the restricting portion 28 and the rear surface of the stopper 25 are arranged at the same position in the front-rear direction. That is, the length from the rear surface of the restricting portion 28 to the rear end of the receiving portion is the same as or slightly smaller than the dimension in the front-rear direction of the ferrite core 10 (core structure 11A, 11B), like the stopper 25. Set to dimensions.

Next, an operation process for attaching the noise filter Fa of Reference Example 1 to the conductive path 30 will be described. First, the conductive path 30 is accommodated in the case 20 from the peripheral surface opening 24, and then the first core structure 11 </ b> A is accommodated in the accommodating space 29 configured by the receiving portion 21 and the stopper 25. At this time, the work can be easily performed by inserting the first core constituting body 11A from the rear opening 27R. Note that the first core structure 11A may be set in the case 20 (accommodating space 29) in advance before the conductive path 30 is accommodated in the case 20.

  Thereafter, the second core constituting body 11B is mounted in the case 20 from the rear opening 27R. At this time, it is possible to avoid interference between the second core constituting body 11 </ b> B and the elastic bending 22 by expanding and deforming the upper and lower elastic pressing pieces 22 diagonally rightward. The second core configuration body 11B is accommodated in an empty space on the right side of the case 20 relative to the first core configuration body 11A. The second core constituent body 11B accommodated in the case 20 has a relative displacement forward relative to the case 20 in the same manner as the first core constituent body 11A because the restricting portion 28 is locked to the outer peripheral edge of the front end face. Be regulated.

  Further, when the second core constituent body 11B is attached to the case 20, the elastic pressing piece 22 is elastically pressed toward the left (the first core constituent body 11A side) against the outer peripheral surface of the second core constituent body 11B. To do. Due to the elastic pressing action of the elastic pressing piece 22, both core constituent bodies 11 </ b> A and 11 </ b> B are laterally moved between the receiving portion 21 and the elastic pressing piece 22 (direction parallel to the direction in which both core constituent bodies 11 </ b> A and 11 </ b> B are combined). The opposed surfaces 12A and 12B of the core constituting bodies 11A and 11B are in close contact with each other. Further, both core constituent bodies 11 </ b> A and 11 </ b> B are held in the case 20 by friction caused by the elasticity of the elastic pressing portion 22.

  As described above, the core structures 11A and 11B are combined to form the ferrite core 10, and at the same time, the attachment of the ferrite core 10 to the case 20 (assembly of the noise filter Fa) is completed. The temporary assembly work of the noise filter Fa is also completed. Thereafter, the adhesive tape 31 is wound around the outer periphery of the case 20 to prevent the elastic pressing piece 22 from expanding in diameter. Although not shown, the tape 31 is wound around the conductive path 30 from both front and rear ends of the case 20. As described above, the work for attaching the ferrite core 10 to the conductive path 30 is completed.

The noise filter Fa according to the first reference example includes a cylindrical ferrite core 10 configured by combining the first and second core structural bodies 11A and 11B divided in the circumferential direction, and the ferrite core 10 in a combined state. And a case 20 made of synthetic resin provided with a means for holding, and it is an object to manufacture the case 20 at low cost. As a means for solving the problem, the case 20 is cantilevered from the receiving portion 21 that makes contact with the outer peripheral surface of the first core constituting body 11A, and the edge portion in the circumferential direction of the receiving portion 21, And an elastic pressing piece 22 that elastically presses the outer periphery of the core structure 11B toward the receiving portion 21 side.

  The elastic pressing piece 22 functions as means for holding the first core constituting body 11A and the second core constituting body 11B in a combined state. The elastic pressing piece 22 is an edge portion in the circumferential direction of the receiving portion 21. It is the form extended from the cantilever. Therefore, it is not necessary to form a slit in a form that is partially removed in the case 20, and the structure of a mold (not shown) for molding the case 20 is simplified to reduce the manufacturing cost of the case 20. can do.

  Further, since the front end portion of the receiving portion 21 is formed with a stopper 25 that can regulate displacement of the first core constituting body 11A accommodated in the receiving portion 21 in the axial direction, the first core constituting body It is possible to prevent 11A from moving away from the receiving portion 21 by moving in the axial direction. Further, the front end portion of the elastic pressing piece 22 is formed with a regulating portion 28 that can regulate the displacement of the second core constituting body 11B pressed against the elastic pressing piece 22 in the axial direction. It is also possible to prevent the two-core structural body 11B from moving away from the elastic pressing piece 22 by moving in the axial direction.

< Example 1 >
Next, an embodiment 1 embodying the present invention with reference to Figs. In the first embodiment , for the front-rear direction, the left side in FIG. 7 is defined as the front and the right side in FIG. 9 is defined as the front. For the left-right direction and the up-down direction, the directions appearing in FIGS. 5, 6, and 8 are defined as right, left, upper, and lower as they are.

The noise filter Fb of the first embodiment is attached so as to surround the conductive path 70 such as a wire harness or various electric wires, and removes noise from the conductive path 70. The noise filter Fb includes a ferrite core 40, a case 50, and a holder 60. The ferrite core 40 is configured by combining a pair of symmetrical first and second core constituting bodies 41A and 41B having a semi-cylindrical shape into a cylindrical shape. The inner diameter of the ferrite core 40 is set to be slightly larger than the outer diameter of the conductive path 70. In order to sufficiently exhibit the noise removal function of the ferrite core 40, it is preferable that the facing surfaces 42A and 42B in the circumferential direction of the core constituent bodies 41A and 41B are in close contact with each other. A case 50 to be described later is provided with means for bringing the core components 41A and 41B into close contact with each other.

  The case 50 is made of a synthetic resin and is a single part having a vertically symmetrical shape. As shown in FIGS. 6 and 7, the case 50 includes a semi-cylindrical receiving portion 51 arranged in the left half region of the case 50 and a pair of vertically symmetrical elastic pressing pieces 53 thinner than the receiving portion 51. It is prepared for. The formation area of the elastic pressing piece 53 in the front-rear direction (axial direction) is the same range as the formation area of the receiving portion 51. The formation region of the receiving portion 51 in the circumferential direction is a range extending over a half circumference (that is, 180 °). The radius of curvature of the inner peripheral surface of the receiving portion 51 is substantially the same as the radius of curvature of the outer peripheral surface of the ferrite core 40 (core components 41A and 41B). 41 A of 1st core structures are attached to the inner peripheral surface of the receiving part 51 in the state which stuck the outer peripheral surface. On the outer periphery of the receiving portion 51, a rotation suppressing portion 52 is formed in a form in which a substantially central portion in the vertical direction is bulged in an arc shape toward the outer peripheral side (left side).

  The pair of elastic pressing pieces 53 has a form that extends in a cantilever shape obliquely rightward from the both end edges in the circumferential direction of the receiving portion 51 along the circumferential direction. The formation area of one elastic pressing piece 53 in the circumferential direction is a range smaller than ¼ circumference (90 °). Accordingly, a right peripheral surface opening 55 that extends along the front-rear direction and that is open to both front-rear ends of the case 50 is formed between the extended end edges 54 of the upper and lower elastic pressing pieces 53.

  The inner peripheral surface of the base end edge portion in the circumferential direction of the elastic pressing piece 53 and the inner peripheral surface of both end edge portions in the circumferential direction of the receiving portion 51 are smoothly continuous (that is, the curvature changes greatly) , In series so that there is no step. Before the ferrite core 40 is attached to the case 50, the radius of curvature of the inner peripheral surface of the elastic pressing piece 53 is set to be slightly smaller than the radius of curvature of the outer peripheral surfaces of the core constituting bodies 41A and 41B. The radial dimension from the center of the arc of the receiving portion 51 to the inner peripheral surface of the extending end edge portion 54 of the elastic pressing piece 53 is the inner peripheral surface of the receiving portion 51 (the outer periphery of the core components 41A and 41B). Surface) is set to a size smaller than the radius of curvature. Further, the radius of curvature of the outer peripheral surface of the elastic pressing piece 53 is smaller than the radius of curvature of the outer peripheral surface of the receiving portion 51. A boundary portion between the receiving portion 51 and the elastic pressing piece 53 in the outer peripheral surface of the case 50 has a step shape.

  Since the thickness of the receiving portion 51 is set to be relatively large, the receiving portion 51 hardly deforms to change the curvature. On the other hand, since the elastic pressing piece 53 is set to have a thickness dimension smaller than that of the receiving portion 51, the elastic pressing piece 53 is displaced in the radial direction with the base end edge portion serving as a substantial fulcrum (that is, to expand the diameter). B) It can be elastically bent. Along with the elastic deflection of the elastic pressing piece 53, the extended end edge 54 of the elastic pressing piece 53 is displaced in the radial direction, and the elastic pressing piece 53 has a receiving portion 51 (case 50). A radially inward biasing force that is displaced toward the center of the cylinder is accumulated.

  A case-side stopper 56 is formed at the front end portion (one end portion in the axial direction) of the case 50. The formation range of the case-side stopper 56 in the circumferential direction is a range extending over the entire inner peripheral region of the receiving portion 51 and the base end portions of the upper and lower elastic pressing pieces 53 (that is, in the existence region of one core structure 41A, 41B). It is a range wider than a certain 180 °). The stopper side stopper has a form extending in a plate shape from the receiving portion 51 and the elastic pressing piece 53 to the inside (center side of the case 50). The front view shape of the inner peripheral edge 57 (extended end edge) of the case side stopper 56 is a semicircular shape concentric with the receiving portion 51. The radius of curvature of the inner peripheral edge 57 of the case side stopper 56 is set to be the same as or slightly smaller than the radius of curvature of the outer peripheral surface of the conductive path 70. The dimension from the rear surface of the case-side stopper 56 to the rear end of the receiving portion 51 is set to be the same as or slightly larger than the length and dimension in the axial direction of the ferrite core 40 (core structure 41A, 41B). ing. The rear end surface of the case 50 (the end surface on the side where the case side stopper 56 is not formed) is a rear surface opening 58 that is open over the entire region.

  The holder 60 is made of synthetic resin and is a single part having a vertically symmetrical shape. As illustrated in FIGS. 8 and 9, the holder 60 includes a semi-cylindrical high-rigidity portion 61 disposed in the right half region of the case 50 and a pair of vertically symmetric low-rigidity portions 62. . The formation region of the low rigidity portion 62 in the front-rear direction (axial direction) is the same range as the formation region of the high rigidity portion 61. The formation region of the high-rigidity portion 61 in the circumferential direction is a range extending over a half circumference (that is, 180 °), and corresponds to the upper and lower elastic pressing pieces 53 and the right peripheral surface opening 55 of the case 50. The radius of curvature of the inner peripheral surface of the high-rigidity portion 61 is larger than the radius of curvature of the outer peripheral surface of the ferrite core 40 (core structure 41A, 41B) (contacts the ferrite core 40 when the holder 60 and the case 50 are assembled). Not set to dimension).

  The pair of low-rigidity parts 62 are in a cantilever shape extending obliquely leftward from both edge portions in the circumferential direction of the high-rigidity part 61 along the circumferential direction. The formation region of one low-rigidity portion 62 in the circumferential direction is a range smaller than ¼ circumference (90 °), and the region where the rotation suppression portion 52 is not formed in the receiving portion 51 of the case 50 (rotation suppression) This is a range corresponding to the region above and below the portion 52). Between the extended end edge portions of the upper and lower low-rigidity portions 62, a left peripheral surface opening 63 is formed that extends along the front-rear direction and is open to both front-rear ends of the case 50. The left peripheral surface opening 63 corresponds to the rotation suppressing portion 52 of the case 50 in the circumferential direction.

  The inner peripheral surface of the base end edge portion in the circumferential direction of the low-rigidity portion 62 and the inner peripheral surface of both end edge portions in the circumferential direction of the high-rigidity portion 61 are connected to form a step shape. This is so arranged that the high-rigidity portion 61 faces the outer peripheral surface of the elastic pressing piece 53, and the low-rigidity portion 62 faces the outer peripheral surface of the receiving portion 51 having a larger radius of curvature than the outer peripheral surface of the elastic pressing piece 53. It is because it is arranged to do. That is, the curvature radius of the inner peripheral surface of the low-rigidity portion 62 is set larger than the curvature radius of the inner peripheral surface of the high-rigidity portion 61. Before the holder 60 is attached to the case 50, the radius of curvature of the inner peripheral surface of the low-rigidity portion 62 is set to be slightly smaller than the radius of curvature of the outer peripheral surface of the receiving portion 51. The radial dimension from the center of the arc of the high-rigidity portion 61 to the inner peripheral surface of the extended end portion of the low-rigidity portion 62 is set to be smaller than the radius of curvature of the inner peripheral surface of the high-rigidity portion 61. ing.

  Since the thickness dimension of the high-rigidity portion 61 is set to be relatively large, deformation that changes the curvature hardly occurs. On the other hand, since the thickness dimension of the low-rigidity part 62 is set smaller than that of the high-rigidity part 61, the diameter of the low-rigidity part 62 is increased (that is, the diameter of the low-rigidity part 62 is increased). So that it can be elastically bent. Along with the elastic bending of the low rigidity portion 62, the extended end edge portion of the low rigidity portion 62 is displaced outward in the radial direction, and the extended end edge portion of the low rigidity portion 62 is moved to the high rigidity portion 61 (holder 60). ) Is biased so as to be displaced toward the center side.

  A holder-side stopper 64 is formed at the rear end portion (one end portion in the axial direction) of the holder 60. The formation range of the holder-side stopper 64 in the circumferential direction is a range extending from the entire inner circumference of the high-rigidity portion 61 to the base end portions of the upper and lower low-rigidity portions 62 (that is, the existence region of one core structure 41A, 41B). Is wider than 180 °). The holder-side stopper 64 has a form extending in a plate shape from the high-rigidity portion 61 and the low-rigidity portion 62 to the inside (center side of the holder 60). The front view shape of the inner peripheral edge 65 (extended end edge) of the holder-side stopper 64 is a semicircular shape concentric with the high-rigidity portion 61. The radius of curvature of the inner peripheral edge 65 of the holder-side stopper 64 is set to the same dimension as the radius of curvature of the inner peripheral edge of the case-side stopper 56, that is, the same or slightly smaller than the radius of curvature of the outer peripheral surface of the conductive path 70. Has been. The dimension from the front surface of the holder-side stopper 64 to the front end of the high-rigidity portion 61 is set to be the same as or slightly larger than the axial length and dimension of the ferrite core 40 (core components 41A and 41B). ing. The front end surface of the holder 60 (the end surface on which the holder-side stopper 64 is not formed) is a front opening 66 that is open over the entire region.

Next, an operation process for attaching the noise filter Fb of the first embodiment to the conductive path 70 will be described. First, the conductive path 70 is accommodated in the case 50 from the right peripheral surface opening 55, and then the first core construct 41 </ b> A is accommodated in the accommodating space 59 constituted by the receiving portion 51 and the case side stopper 56. At this time, if the first core constituting body 41 </ b> A is inserted into the case 50 from the rear opening 58, the first core constituting body 41 </ b> A does not need to interfere with the receiving portion 51 and the elastic pressing piece 53. Note that the first core constituting body 41A may be set in the case 50 (accommodating space 59) in advance before the conductive path 70 is accommodated in the case 50. The first core constituting body 41 </ b> A accommodated in the case 50 is restricted from moving forward relative to the case-side stopper 56 by contacting the case-side stopper 56.

  Thereafter, the second core constituting body 41 </ b> B is attached in the case 50 from the rear opening 58. At this time, it is possible to avoid interference between the second core constituting body 41 </ b> B and the elastic pressing piece 53 by expanding and deforming the upper and lower elastic pressing pieces 53 obliquely to the right. The second core structure 41B is accommodated in an empty space on the right side of the case 50 in the case 50 relative to the first core structure 41A. The second core constituent body 41B accommodated in the case 50 is regulated from moving forward relative to the first core constituent body 41A by bringing the outer peripheral edge of the front end face thereof into contact with the case-side stopper 56. .

  When the second core constituent body 41B is attached to the case 50, the elastic pressing piece 53 is elastically applied to the left side (first core constituent body 41A side) with respect to the outer peripheral surface of the second core constituent body 41B. Touch. Due to the elastic pressing action of the elastic pressing piece 53, both core constituent bodies 41A and 41B are laterally moved between the receiving portion 51 and the elastic pressing piece 53 (a direction parallel to the direction in which both core constituent bodies 41A and 41B are combined). The opposed surfaces 42A and 42B in the circumferential direction of the core constituting bodies 41A and 41B are in close contact with each other. As described above, the core structural bodies 41A and 41B are combined to form the ferrite core 40, and at the same time, the attachment of the ferrite core 40 to the case 50 (assembly of the noise filter Fb) is completed. The temporary assembly work of the case 50 and the ferrite core 40 is also completed.

  Thereafter, the holder 60 is assembled to the case 50 so as to slide from behind. At the time of assembly, the high rigidity portion 61 is brought into sliding contact with the outer peripheral surface of the upper and lower elastic pressing pieces 53 and the upper and lower low rigidity portions 62 are elastically expanded to the left and deformed to the outer peripheral surface of the receiving portion 51. Make sliding contact. In this state, since the rotation suppressing portion 52 of the case 50 enters the left peripheral surface opening 63 of the holder 60, relative rotation of the case 50 and the holder 60 in the circumferential direction is restricted.

  When the case 50 and the holder 60 are slid and the front surface of the holder-side stopper 64 comes into contact with the rear end surface of the case 50, the assembly of the case 50 and the holder 60 is completed. At the same time, the assembly of the noise filter Fb is completed. Since the ferrite core 40 in the case 50 is sandwiched between the case-side stopper 56 and the holder-side stopper 64 in the front-rear direction, the ferrite core 40 is held in the case 50 in a state where movement in the front-rear direction (axial direction) is restricted. The

  The low-rigidity portion 62 elastically contacts the outer peripheral surface of the receiving portion 51 to the right. Due to the elastic pressing action of the low-rigidity portion 62, the receiving portion 51 and the elastic pressing piece 53 are sandwiched between the high-rigidity portion 61 and the low-rigidity portion 62 in the left-right direction. The core structure 41A, 41B is sandwiched in a direction parallel to the direction in which the core structures 41A and 41B are combined. Thereby, opposing surface 42A, 42B in the circumferential direction of both core structure 41A, 41B adheres more reliably.

  After the assembly is completed, the adhesive tape 71 is wound around the outer periphery of the holder 60 and the outer periphery of the rotation suppressing portion 52 of the case 50, so that the elastic pressing piece 53 is expanded and the low-rigidity portion 62 is expanded. Prevent deformation. Although illustration is omitted, a tape is wound around the conductive path 70 from both front and rear ends of the noise filter Fb. As described above, the attaching operation of the ferrite core 40 to the conductive path 70 is completed.

The noise filter Fb of the first embodiment holds the cylindrical ferrite core 40 configured by combining the first and second core constituent bodies 41B divided in the circumferential direction, and the ferrite core 40 in the combined state. And a case 50 made of a synthetic resin provided with means, and it is an object to manufacture the case 50 at low cost. As a means for solving the problem, the case 50 is cantilevered from the receiving portion 51 that makes contact with the outer peripheral surface of the first core constituting body 41A, and the edge portion in the circumferential direction of the receiving portion 51, And an elastic pressing piece 53 that elastically presses the outer periphery of the core structure 41B toward the receiving portion 51 side.

  The elastic pressing piece 53 functions as a means for holding the first core constituting body 41 </ b> A and the second core constituting body 41 </ b> B in a combined state. The elastic pressing piece 53 is an edge portion in the circumferential direction of the receiving portion 51. It is the form extended from the cantilever. Therefore, it is not necessary to form a slit in a form that is partially removed in the case 50, and the structure of a mold (not shown) for molding the case 50 is simplified, and the manufacturing cost of the case 50 is reduced. can do.

Further, the noise filter Fb of the first embodiment includes a holder 60 that is fitted around a part of the case 50 in the circumferential direction. The holder 60 is cantilevered from the circumferential edge of the high-rigidity portion 61 in a cantilevered manner, and is elastic to the outer circumference of the receiving portion 51. And a low-rigidity portion 62 that comes into contact with. Accordingly, since the elastic pressing piece 53 is deformed to expand outward in the radial direction can be reliably restricted by the radially inward elastic restoring force accumulated in the low rigidity portion 62, the first core constituting body 41A. And the second core structure 41B can be securely held in close contact with each other.

  Furthermore, at the front end of the case 50 (the receiving portion 51 and the elastic pressing piece 53), both the first core constituting body 41A and the second core constituting body 41B accommodated in the case 50 are displaced forward in the axial direction. A case side stopper 56 capable of regulating the above is formed. A rear opening 58 is opened at the rear end of the case 50 over the entire region. Therefore, the operation | work which accommodates core structure 41A, 41B in case 50 can be performed easily. Moreover, the case 50 can be formed only by a mold that is opened in the front-rear direction, and a slide mold is not required.

  On the other hand, at the rear end of the holder 60 (the high rigidity portion 61 and the low rigidity portion 62), both the first core structure 41A and the second core structure 41B housed in the case 50 are axially rearward (case side). A holder side stopper 64 capable of restricting displacement to the side opposite to the stopper 56 is formed. A front opening 66 is opened at the front end of the holder 60 over the entire region. Therefore, similarly to the case 50, the holder 60 can be formed only by a mold that is opened in the front-rear direction, and a slide mold is unnecessary. And in the state which assembled | attached case 50 and the holder 60, the ferrite core 40 in case 50 can be hold | maintained by pinching between the case side stopper 56 and the holder side stopper 64. FIG.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the first embodiment, the case side stopper is formed on the case and the holder side stopper is formed on the holder as means for restricting the movement of the first core structure and the second core structure in the axial direction. However, a pair of stoppers may be formed only on the case, or a pair of stoppers may be formed only on the holder.
(2) In the first embodiment, the pair of elastic pressing pieces are extended from both end edge portions in the circumferential direction of the receiving portion, but the elastic pressing piece is only one edge portion in the circumferential direction of the receiving portion. The form extended from may be sufficient.
(3) In the first embodiment, the ferrite core and the case have a substantially cylindrical shape, but the ferrite core and the case may have a rectangular tube shape.
<Other reference examples>
(1) Although the stopper is formed in the receiving part in the reference example 1, it is also conceivable that the stopper is not formed in the receiving part.
(2) In the above reference example 1, the restricting portion is formed on the elastic pressing piece, but it is also conceivable that the restricting portion is not formed on the elastic pressing piece.
(3) It is also conceivable that a holder having a high-rigidity portion and a low-rigidity portion is externally fitted to the case of the reference example 1 as in the first embodiment. In this case, the holder side stopper of the holder may be left as it is, and among the pair of stoppers and the restriction portion formed in the case of Reference Example 1, the stopper and the restriction portion on the same side as the holder side stopper in the axial direction may be removed. Alternatively, the holder-side stopper may be removed from the holder while leaving the pair of stoppers and the restricting portion as they are.
(4) In the reference example 1, the pair of elastic pressing pieces are extended from both end edges in the circumferential direction of the receiving portion. However, the elastic pressing pieces are used only in one end edge portion in the circumferential direction of the receiving portion. It is also possible to adopt a form extending from
(5) In the reference example 1, the ferrite core and the case have a substantially cylindrical shape, but it is also conceivable that the ferrite core and the case have a rectangular tube shape.

Fa ... Noise filter 10 ... Ferrite core 11A ... First core structure 11B ... Second core structure 20 ... Case 21 ... Receiving part 22 ... Elastic pressing piece 25 ... Stopper 28 ... Restriction part Fb ... Noise filter 40 ... Ferrite core 41A ... 1st core structure 41B ... 2nd core structure 50 ... Case 51 ... Receiving part 53 ... Elastic pressing piece 56 ... Case side stopper 60 ... Holder 61 ... High rigidity part 62 ... Low rigidity part 64 ... Holder side stopper

Claims (4)

A ferrite core having a cylindrical shape in which the first and second core components divided in the circumferential direction are combined;
A case made of synthetic resin for housing the ferrite core ;
A holder that is fitted on a part of the case in the circumferential direction ;
The case is
A receiving portion for contacting the outer peripheral surface of the first core component;
An elastic pressing piece that extends in a cantilevered manner from an end edge in the circumferential direction of the receiving portion and is elastically deflectable in the radial direction, and elastically presses the outer periphery of the second core component toward the receiving portion. And configured with
The holder is
A highly rigid portion capable of contacting the outer periphery of the elastic pressing piece;
The high-rigidity portion includes a low-rigidity portion that extends in a cantilevered manner from an edge portion in the circumferential direction of the high-rigidity portion and can be elastically bent in the radial direction and elastically abuts against the outer periphery of the receiving portion. A noise filter characterized by   The stopper in which the position shift of the said 1st core structural body accommodated in the said receiving part to an axial direction is formed in the edge part in the axial direction of the said receiving part is characterized by the above-mentioned. The noise filter described.   A restriction portion capable of restricting displacement of the second core structural body pressed by the elastic pressing piece in the axial direction is formed at an end portion in the axial direction of the elastic pressing piece. The noise filter according to claim 1 or 2. It is possible to restrict displacement of the first core constituent body and the second core constituent body accommodated in the case in the axial direction at one end portion in the axial direction of the receiving portion and the elastic pressing piece. Case side stopper is formed,
At the other end in the axial direction of the high-rigidity portion and the low-rigidity portion, the first core constituent and the second core constituent housed in the case are opposite to the case-side stopper in the axial direction. The noise filter according to claim 1, wherein a holder-side stopper capable of restricting displacement to the side is formed .

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