JP6319662B2 - Noise filter - Google Patents

Description

  The present invention relates to a noise filter.

  Patent Document 1 discloses a noise filter including a ferrite core that surrounds a conductive path and a filter case that houses the ferrite core. The filter case is configured by combining a pair of case components, and locks both case components in the combined state by locking the lock portions formed on both case components. . The lock portion has a structure in which a protruding piece formed on one case component is inserted into a recess formed on the other case component so that the lock cannot be easily released for a general user.

JP 2014-110343 A

  However, the lock portion of the noise filter is formed on the outer surface of the case structure. Therefore, if a special tool is used, even a general user can unlock the lock portion and disassemble the noise filter.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide a noise filter that cannot be disassembled.

The present invention
A ferrite core surrounding the conductive path;
A filter case configured by combining the first case structure and the second case structure, and housing the ferrite core;
A first lock portion formed on the inner surface of the first case structure;
A second lock portion formed on an inner surface of the second case structure and locking the first case structure and the second case structure by being engaged with the first lock portion ;
The inner peripheral surfaces of the first case structure and the second case structure are in a form protruding radially inward, and a positioning portion for positioning the ferrite core in the axial direction of the conductive path is formed,
It is characterized in that a part of the positioning part is the first lock part and the second lock part .

According to this structure, since the 1st lock part and the 2nd lock part are formed in the inner surface of a case structure, if both case structures are locked to a united state, both lock parts will be locked from the outside of a filter case Cannot be released. Therefore, the noise filter of the present invention cannot be disassembled. Moreover, since the positioning part also serves as the lock part, the shape of the case structure can be simplified as compared with the case where the lock part is formed separately from the positioning part.

Sectional drawing which shows the noise filter of Example 1 cut | disconnected at right angles to the axis line of a conductive path XX sectional view of FIG.

The present invention is a noise filter applied to a conductive path in a form in which a wire harness is surrounded by a corrugated tube, and protrudes radially inward from the inner peripheral surfaces of the first case structure and the second case structure. The movement restricting portion that restricts the movement of the corrugated tube in the axial direction of the conductive path is formed by selectively locking to a part of the plurality of grooves formed on the outer periphery of the corrugated tube. In addition, a part of the movement restricting portion may be the first lock portion and the second lock portion.
According to this configuration, since the movement restricting portion also serves as the lock portion, the shape of the case structure can be simplified as compared with the case where the lock portion is formed separately from the movement restricting portion.

<Example 1>
Embodiment 1 of the present invention will be described below with reference to FIGS. The noise filter F of the present embodiment includes an annular ferrite core 10 and a filter case 20 that houses the ferrite core 10. The ferrite core 10 is configured by combining a pair of core structural bodies 11 having a semi-cylindrical shape. The noise filter F is applied to the conductive path 50 in a form in which a wire harness 51 in which a plurality of electric wires (not shown) are bundled is surrounded by a corrugated tube 52, and the noise of the electric wires constituting the wire harness 51 is removed by the ferrite core 10. To do. The inner diameter of the ferrite core 10 is set to be slightly larger than the maximum outer diameter of the corrugated tube 52.

  The filter case 20 is composed of two parts, a first case structure 21 made of a synthetic resin and a second case structure 22 made of a synthetic resin. By combining the case structure bodies 21 and 22, the filter case 20 is electrically conductive as a whole. A cylindrical shape concentric with the axis of the path 50 is formed. A large portion of the internal space of the filter case 20 excluding both end portions in the axial direction is an accommodation space 23 for accommodating the ferrite core 10. Moreover, the outer wall part 24 which makes a ring shape is formed at both ends in the axial direction of the filter case 20. The inner diameter of the center hole 25 of the outer wall portion 24 is set to a dimension that is slightly larger than the maximum outer diameter dimension of the conductive path 50.

  The 1st case structure 21 is provided with the 1st surrounding wall part 26 which makes a semicylindrical shape, and a pair of 1st end wall part 27 which makes a semicircular arc shape. The pair of first end wall portions 27 protrude radially inward from both axial end edges of the first peripheral wall portion 26 to constitute the outer wall portion 24. A pair of first positioning portions 28 (movement restricting portions described in claims) are formed in the first case structure 21 so as to protrude radially inward from the inner peripheral surface of the first peripheral wall portion 26. ing. The pair of first positioning portions 28 is disposed in a region between the pair of first end wall portions 27 and is disposed in the vicinity of the first end wall portion 27.

  A semicircular space defined by the pair of first positioning portions 28 and the first peripheral wall portion 26 is a first accommodation recess 29 that constitutes the accommodation space 23. When the core component 11 is accommodated in the first accommodating recess 29, the pair of first positioning portions 28 are in a positional relationship in which they contact or approach each other end surface in the axial direction of the core component 11. Accordingly, the pair of first positioning portions 28 restricts the core structure 11 from moving relative to the filter case 20 in the axial direction.

  The pair of first positioning portions 28 has a substantially semicircular arc shape as a whole, and an inner peripheral edge thereof forms a semicircular shape concentric with the conductive path 50. The radius of curvature of the inner peripheral edge of the first positioning portion 28 is smaller than the radius of the outermost periphery of the corrugated tube 52 and slightly larger than the radius of the outer periphery of the plurality of groove portions 53 formed on the outer periphery of the corrugated tube 52. Is set. Further, the thickness dimension of the first positioning portion 28 in the axial direction is set to be slightly smaller than the minimum groove width of the groove portion 53.

  The 2nd case structure 22 is provided with the 2nd surrounding wall part 30 which makes a semicylindrical shape, and a pair of 2nd end wall part 31 which makes a semicircular arc shape. The pair of second end wall portions 31 protrudes radially inward from both axial edges of the second peripheral wall portion 30 to form the outer wall portion 24. A pair of second positioning portions 32 (movement restricting portions described in claims) that protrude in a wall shape radially inward from the inner peripheral surface of the second peripheral wall portion 30 is formed inside the second case structure 22. ing. The pair of second positioning portions 32 is disposed in a region between the pair of second end wall portions 32 and is disposed in the vicinity of the second end wall portion 32.

  A semicircular space defined by the pair of second positioning portions 32 and the second peripheral wall portion 30 is a second accommodation recess 33 that constitutes the accommodation space 23. When the core component 11 is accommodated in the second accommodating recess 33, the pair of second positioning portions 32 are in a positional relationship in which they contact or approach each other end surface in the axial direction of the core component 11. As a result, the pair of second positioning portions 32 restricts the core structure 11 from moving relative to the filter case 20 in the axial direction.

  The pair of second positioning portions 32 has a substantially semicircular arc shape as a whole, and an inner peripheral edge thereof forms a semicircular shape concentric with the conductive path 50. The curvature radius of the inner peripheral edge of the second positioning portion 32 is the same as the curvature radius of the inner peripheral edge of the first positioning portion 28. Further, the thickness dimension in the axial direction of the second positioning portion 32 is set to be slightly smaller than the minimum groove width of the groove portion 53.

  When both case components 21 and 22 are combined, both end edges in the circumferential direction of the first peripheral wall portion 26 and the second peripheral wall portion 30 come into contact with each other, and the circumferential direction of the first end wall portion 27 and the second end wall portion 31. Both edges of the abut against each other. As a result, the internal space of the filter case 20 becomes a protective space 34 from which foreign matter cannot enter. In the protection space 34, a pair of first positioning portions 28 and a pair of second positioning portions 32 are accommodated. The accommodation space 23 constitutes a part of the protection space 34.

  Each of the pair of first positioning portions 28 is formed with a pair of first locking portions 35 that protrude in a cantilevered manner from both end edges in the circumferential direction toward the second positioning portion 32. The protruding direction of the first lock portion 35 is a direction substantially parallel to the direction in which the case structural bodies 21 and 22 are combined. The formation area of the first lock portion 35 in the axial direction matches the entire thickness range of the first positioning portion 28, and the thickness dimension in the axial direction of the first lock portion 35 is the same as that of the first positioning portion 28. is there. Therefore, the first lock part 35 has a function of positioning the core structure 11 in the axial direction, like the first positioning part 28.

  A lock protrusion 36 that protrudes radially outward (that is, in a direction toward the inner peripheral surface of the second peripheral wall portion 30) is formed on the protruding end portion of the first lock portion 35. The locking protrusion 36 is formed with a first locking surface 37 that is perpendicular to the protruding direction of the first locking portion 35, and a first guide surface 38 that is inclined with respect to the protruding direction of the first locking portion 35. Further, the first lock portion 35 can be elastically bent in a direction opposite to the protruding direction of the lock protrusion 36 (inward in the radial direction). The first lock portion 35 is also housed in the protective space 34, as with the first positioning portion 28.

  Each of the pair of second positioning portions 32 is formed with a pair of cutout portions 39 in a form in which a part of both end edges in the circumferential direction is cut out. The formation region of the notch 39 in the radial direction is limited to the outer peripheral side range. Therefore, in the state where both case components 21 and 22 are combined, the inner peripheral edge portion of the second positioning portion 32 is continuous with the inner peripheral edge portion of the first positioning portion 28, and the inner peripheral edge portions of both positioning portions 28 and 32 are all around. Continuous.

  In the second case structure 22, two pairs of second lock portions 40 that protrude radially inward from the inner peripheral surface of the second peripheral wall portion 30 into the notches 39 are formed. The formation area of the second lock portion 40 in the axial direction matches the entire thickness range of the second positioning portion 32. That is, the thickness dimension of the second lock part 40 in the axial direction is the same as that of the second positioning part 32. Therefore, the 2nd lock part 40 constitutes the 2nd positioning part 32, and has the function to position core composition 11 in the direction of an axis. The second locking portion 40 includes a second locking surface 41 that is perpendicular to the direction in which both case components 21 and 22 are combined, and a second guide surface 42 that is inclined with respect to the direction in which both case components 21 and 22 are combined. Is formed.

  Next, the procedure for assembling the noise filter F of this embodiment and attaching it to the conductive path 50 will be described. First, the core structure 11 is housed in the first housing recess 29 and the second housing recess 33, respectively. Next, the conductive path 50 is attached to one core structure 11. And both case structure 21 and 22 are united, and both core structure 11 is united simultaneously. In the process of combining, the first lock portion 35 enters the cutout portion 39, and the first guide surface 38 contacts the second guide surface 42. Thereafter, when the uniting operation is advanced, both the guide surfaces 38 and 42 are in sliding contact with each other, and the first lock portion 35 is elastically bent radially inward.

  When both case components 21 and 22 reach the proper combined state, the lock projection 36 passes through the second lock portion 40, so that the first lock portion 35 is elastically restored, and the first locking surface 37 and the second lock The locking surface 41 abuts in parallel with the uniting direction. Due to the locking action of both the locking surfaces 37, 41, both case components 21, 22 are locked in a state where they are restricted from being separated (unioned state). In addition, regarding the axial direction, the relative movement of both case components 21 and 22 is restricted by the locking action of locking portions (not shown) formed on the peripheral wall portions 26 and 30 and the end wall portions 27 and 31. .

  The locking of the first lock portion 35 and the second lock portion 40 is performed inside the protective space 34 of the filter case 20. Since the protective space 34 is blocked from the outside of the filter case 20, a tool or the like cannot be inserted into or hooked to the locking portions of the lock portions 35 and 40. In order to unlock the lock portions 35 and 40, it is necessary to destroy the peripheral wall portions 26 and 30 and the end wall portions 27 and 31. Further, the inner peripheral edge portions of the first positioning portion 28 and the second positioning portion 32 are fitted into any one of the plurality of groove portions 53 on the outer periphery of the corrugated tube 52. By this fitting, relative movement in the axial direction of the corrugated tube 52 with respect to the filter case 20 and the ferrite core 10 is restricted.

  As described above, the noise filter F of the present embodiment is configured by combining the ferrite core 10 that surrounds the conductive path 50, the first case structure 21, and the second case structure 22, and accommodates the ferrite core 10. The filter case 20 is provided. A first lock portion 35 is formed on the inner surface of the first case structure 21, and the case structure bodies 21 and 22 are combined on the inner surface of the second case structure 22 by engaging with the first lock portion 35. A second lock portion 40 that locks in a state is formed. According to this structure, since the 1st lock part 35 and the 2nd lock part 40 are formed in the inner surface of case structure 21 and 22, when both case structure 21 and 22 are locked to a combined state, filter case 20 The locked state of both lock portions 35 and 40 cannot be released from the outside. Therefore, the noise filter F cannot be disassembled without being destroyed.

  In addition, the inner peripheral surfaces of the first case structure 21 and the second case structure 22 protrude radially inward and position the ferrite core 10 in the axial direction of the conductive path 50. 28 and a second positioning portion 32 are formed. A part of the first positioning part 28 functions as the first lock part 35, and a part of the second positioning part 32 functions as the second lock part 40. According to this configuration, since the positioning portions 28 and 32 also serve as the lock portions 35 and 40, the case components 21 and 22 are compared with the case where the lock portions 35 and 40 are formed separately from the positioning portions 28 and 32. The shape is simplified.

  Further, the conductive path 50 has a form in which the wire harness 51 is surrounded by a corrugated tube 52. Further, the inner peripheral surfaces of the first case constituent body 21 and the second case constituent body 22 each have a form protruding radially inward, and one of the plurality of grooves 53 formed on the outer periphery of the corrugated tube 52. The first positioning part 28 and the second positioning part 32 that restrict the movement of the corrugated tube 52 in the axial direction of the conductive path 50 are formed by being selectively latchable with the part. Further, a part of the first positioning part 28 serves as the first lock part 35, and a part of the second positioning part 32 serves as the second lock part 40. According to this structure, since the means (positioning parts 28 and 32) for restricting the movement of the corrugated tube 52 also serves as the lock parts 35 and 40, the shapes of the case components 21 and 22 are simplified.

<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 above embodiment, the ferrite core is configured by combining a pair of core components, but the ferrite core may be an annular single member.
(2) In the said Example, although the 1st case structure and 2nd case structure which comprise a filter case are separate components, connecting a 1st case structure and a 2nd case structure with a hinge. Thus, the filter case may be a single component.
(3) In the above embodiment, the conductive path is configured by inserting a plurality of electric wires through the corrugated tube, but the conductive path is not surrounded by one electric wire or corrugated tube that is not surrounded by the corrugated tube. A plurality of electric wires (wire harnesses) may be used. Moreover, when not enclosing with a corrugated tube, you may wind a soft tape around the outer periphery of one or several electric wires.
(4) In the above embodiment, the first case structure and the second case structure have different shapes, but the first case structure and the second case structure may have the same shape. In this case, one lock arm and one lock protrusion are formed on each of the first case structure and the second case structure, and the lock arm of the first case structure and the lock protrusion of the second case structure are engaged. Then, the lock protrusion of the first case structure and the lock arm of the second case structure may be engaged.
(5) In the above embodiment, a part of the movement restricting part for restricting the movement of the corrugated tube in the axial direction is made to function as a lock part, but the lock part may be formed separately from the movement restricting part. Good.
(6) In the above embodiment, the positioning unit also has the function of the movement restricting unit, but the positioning unit and the movement restricting unit may be formed separately.
(7) In the said Example, although the lock part protruded from the internal peripheral surface of a case structure, you may make a lock part protrude from the end wall part of a case structure.
<Reference example>
(1) In the above embodiment, a part of the positioning portion for positioning the ferrite core in the axial direction is functioned as a lock portion. However, as a reference example of the present invention, the lock portion is formed separately from the positioning portion. The form to do is also considered.

F ... Noise filter 10 ... Ferrite core 20 ... Filter case 21 ... First case component 22 ... Second case component 28 ... First positioning part (movement restricting part)
32 ... 2nd positioning part (movement control part)
35 ... 1st lock part 40 ... 2nd lock part 50 ... Conductive path 51 ... Wire harness 52 ... Corrugated tube 53 ... Groove part

Claims (2)

A ferrite core surrounding the conductive path;
A filter case configured by combining the first case structure and the second case structure, and housing the ferrite core;
A first lock portion formed on the inner surface of the first case structure;
A second lock portion formed on an inner surface of the second case structure and locking the first case structure and the second case structure by being engaged with the first lock portion ;
The inner peripheral surfaces of the first case structure and the second case structure are in a form protruding radially inward, and a positioning portion for positioning the ferrite core in the axial direction of the conductive path is formed,
A part of the positioning part is the first lock part and the second lock part . A noise filter applied to a conductive path in a form in which a wire harness is surrounded by a corrugated tube,
The inner peripheral surfaces of the first case structural body and the second case structural body protrude radially inward, and selectively engage with some of the plurality of grooves formed on the outer periphery of the corrugated tube. By stopping, a movement restricting portion that restricts movement of the corrugated tube in the axial direction of the conductive path is formed,
The noise filter according to claim 1, wherein a part of the movement restricting portion is the first lock portion and the second lock portion .

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