JP6156076B2 - Noise filter - Google Patents

Description

  The present invention relates to a noise filter.

  Patent Document 1 discloses a noise filter that includes a synthetic resin housing, a ground member made of a metal plate, and a capacitor accommodated in the housing. The housing includes a box-shaped member whose upper surface is opened and a lid member that closes the upper surface of the box-shaped member. The ground member is attached along the bottom wall portion of the box-shaped member, and a connection portion for connecting to the lead wire of the capacitor in the housing is formed in the ground member.

  As a means for connecting the connecting portion and the lead wire, a welding method is preferable from the viewpoint of connection reliability, but there is a concern that the synthetic resin housing is thermally deformed by the welding connection method. In that respect, in the noise filter of Patent Document 1, since the welding position is set to a position close to the opening on the upper surface of the box-shaped member by raising the connection portion upward, the housing is thermally deformed during welding. There is no fear.

Japanese Patent No. 4850181

The noise filter disclosed in Patent Document 1 has a configuration in which the connection portion is raised upward from a ground member arranged along the bottom wall portion of the box-shaped member to a position near the opening on the upper surface of the box-shaped member. By doing so, thermal deformation of the housing during welding can be avoided. However, the shape in which the connecting portion is largely raised upward has a problem that the material cost of the ground member is increased.
The present invention has been completed based on the above situation, and an object thereof is to reduce the material cost of the ground member.

The noise filter of the present invention is
A synthetic resin box-shaped member having an opening;
A metal earth member attached to the box-shaped member so as to have a plate-like main body portion and close the opening with the plate-like main body portion;
Formed in a form protruding on the plate-shaped main body, and connected to the inside of the box-shaped member in a state where the grounding member is assembled to the box-shaped member;
A capacitor housed in the box-shaped member;
A lead wire provided in the capacitor and connected to the connecting portion by welding in the box-shaped member;
It is characterized in that it is provided with a notch that is formed in the plate-like main body and exposes a welding region between the connecting portion and the lead wire to the outside of the box-shaped member.

  The connection between the connecting portion and the lead wire by welding can be made from the outside of the box-shaped member through the notch. Since the cutout portion and the connection portion are formed in the same plate-like main body portion, the projecting dimension of the connection portion can be reduced and the material cost of the ground member can be reduced.

The top view of the noise filter of Example 1 A plan view showing the grounding member removed from the housing XX sectional view of FIG. YY sectional view of FIG.

  (1) The noise filter of this invention may be formed when the said notch raises the said connection part. According to this structure, since the part removed in order to form a notch part is utilized as a connection part, material cost can further be reduced.

  (2) In the noise filter of the present invention, the connecting portion is disposed in the vicinity of the opening edge of the opening, and a welding region with the lead wire in the connecting portion is You may face the opposite side to an opening edge. According to this structure, the influence of the heat with respect to the opening edge of an opening part is reduced in the case of welding.

<Example 1>
Embodiment 1 of the present invention will be described below with reference to FIGS. The noise filter according to the first embodiment includes a housing 10 made of synthetic resin, a terminal fitting 30, a ground member 40, a pair of capacitors 50, and one coil 60. In the following description, the vertical direction is based on the direction shown in FIGS. 3 and 4, and the right and left directions in FIGS.

<Housing 10>
The housing 10 is configured by integrally forming a box-shaped member 12 and a hood portion 22. The box-shaped member 12 includes a bottom wall portion 13 having a square shape in plan view and a square cylindrical peripheral wall portion 14 rising from the outer peripheral edge of the bottom wall portion 13, and an opening portion 15 whose upper surface is opened over the entire region. It has become. The opening 15 is closed by the ground member 40.

  In the box-shaped member 12, a pair of front and rear clamping parts 16 are formed that rise upward from the upper surface of the bottom wall part 13. The pair of sandwiching portions 16 has a function of positioning and supporting the coil 60. Similarly, in the box-shaped member 12, a pair of left and right accommodating portions 17 are formed that rise from the upper surface of the bottom wall portion 13. The interior of the accommodating portion 17 is an accommodating space opened upward, and the capacitor 50 is accommodated in the accommodating portion 17.

  The front wall portion 18 constituting the peripheral wall portion 14 is formed with a positioning groove 19 having a recessed upper end surface (that is, the front edge portion of the opening edge of the opening portion 15). Two pairs of left and right engaging claws 21 projecting upward are formed on the upper edge of the left and right side wall portions 20 constituting the peripheral wall portion 14 with a space in the front and rear direction. The hood portion 22 has a shape that extends forward from the outer peripheral edge of the front wall portion 18 in a rectangular tube shape. The upper surface of the hood part 22 is raised stepwise with respect to the upper surface of the box-shaped member 12 (open cotton of the opening 15). The upper end surface of the locking claw 21 is set to the same height as the upper surface of the hood portion 22.

<Terminal fitting 30>
The terminal fitting 30 has an elongated shape in the front-rear direction as a whole. The pair of terminal fittings 30 are arranged in parallel to the left and right, and are integrated with the housing 10 (box-shaped member 12) by insert molding in a state of passing through the front wall portion 18 in the front-rear direction. The tab 31 constituting the front end side region of the terminal fitting 30 is accommodated in the hood portion 22 and is connected to a mating terminal (not shown) constituting a wire harness (not shown). The rear end portion of the terminal fitting 30 is a welded portion 32 that is bent upward so that the side view is substantially L-shaped. The welded portion 32 is disposed at the upper end in the box-shaped member 12, that is, at a position close to the opening 15. A lead wire 52F of the capacitor 50 is connected to the rear surface of the welded portion 32 by solder 62.

<Earth member 40>
The ground member 40 is formed by punching a metal plate material into a predetermined shape and bending it. The ground member 40 includes a plate-like main body portion 41, a bent portion 42, a ground portion 43, and a connection portion 44. The plate-like main body 41 has a horizontal flat plate shape that is square in plan view as a whole. The plate-like main body portion 41 is formed with positioning ribs 45 bent downward from the front end edge thereof. The bent portion 42 is continuous with the rear end edge of the plate-like main body portion 41. The rear end edge of the bent portion 42 is connected to the front end edge of the ground contact portion 43 that is parallel to the plate-like main body portion 41 and has a substantially square shape in plan view. The grounding portion 43 is formed with a through hole mounting hole 46 having a circular shape in plan view.

  A pair of left and right connection portions 44 are formed in the rear end side region of the plate-like main body portion 41. The connection part 44 is a form in which a part of the plate-like main body part 41 is cut and raised at a substantially right angle downward and rearward. A lead wire 52 </ b> R of a capacitor 50, which will be described later, is connected to the front surface of the connection portion 44 by solder 62. Since the connection portion 44 is cut and raised, a notch portion 47 having a square shape in plan view is formed in a region adjacent to the front of the connection portion 44 in the plate-like main body portion 41. The cutout portion 47 has a form penetrating the plate-like main body portion 41 in the vertical direction, and forms a closed window shape over the entire circumference. The cutout portion 47 is positioned so as to expose the welded region between the connection portion 44 and the lead wire 52 </ b> R to the upper outside of the box-shaped member 12 in plan view. A pair of left and right window holes 48 for welding the welded portion 32 of the terminal fitting 30 and the lead wire 52F are formed in the front end side region of the plate-like main body portion 41.

  In a state in which the ground member 40 is assembled to the housing 10, the plate-like main body portion 41 abuts so as to be placed on the upper end surface of the peripheral wall portion 14, whereby the ground member 40 is relatively displaced downward with respect to the box-shaped member 12. Is regulated. Further, when the positioning rib 45 is fitted in the positioning groove 19, the relative displacement in the front-rear direction of the ground member 40 with respect to the box-shaped member 12 is restricted. Further, the two pairs of locking claws 21 are locked to the left and right side edges of the plate-like main body 41, thereby restricting the relative displacement of the box-shaped member 12 in the upward direction and the relative displacement in the left-right direction. Is done.

  In a state where the ground member 40 is assembled to the box-shaped member 12, the upper surface of the grounding portion 43 is positioned at the same height as the upper surface of the hood portion 22 and the upper end surface of the locking claw 21. Therefore, the noise filter stably abuts the upper surface of the hood portion 22, the upper end surface of the locking claw 21, and the upper surface of the grounding portion 43 against a flat grounding surface (not shown) in the body of the automobile. be able to. In this state, the ground contact portion 43 comes into contact with the ground contact surface in a wide range over the entire area. The ground member 40 is grounded by screwing a bolt (not shown) penetrating the mounting hole 46 into the ground surface.

  In a state in which the ground member 40 is assembled to the box-shaped member 12, a pair of left and right connection portions 44 formed on the ground member 40 are accommodated inside the box-shaped member 12 and the upper end portion of the rear wall portion constituting the peripheral wall portion 14. It is arranged at a position close to the front. That is, the connecting portion 44 is disposed at a position near the rear wall portion of the opening edge of the opening portion 15. Therefore, there is a concern that the heat during the welding operation between the connecting portion 44 and the lead wire 52R may adversely affect the rear wall portion. However, since the welding region of the connecting portion 44 with the lead wire 52R is on the front surface of the connecting portion 44, that is, on the opposite side of the rear wall portion across the connecting portion 44, there is an influence of heat on the rear wall portion. There is no fear.

  In the state in which the ground member 40 is assembled to the box-shaped member 12, the pair of window holes 48 are arranged so as to correspond to the welded portion 32 of the pair of terminal fittings 30 and the rear vicinity region thereof in plan view. Therefore, the window hole 48 exposes the welded region between the welded portion 32 and the lead wire 52F to the upper outside of the box-shaped member 12 in plan view. Since the weld portion 32 is disposed at a position near the front wall portion 18 in the opening edge of the opening portion 15, the heat during the welding operation of the weld portion 32 and the lead wire 52 </ b> F adversely affects the front wall portion 18. There is concern. However, the welding region of the welded portion 32 with the lead wire 52F is on the rear surface of the welded portion 32, that is, on the opposite side of the front wall portion 18 across the welded portion 32. There is no risk of impact.

<Capacitor 50>
The capacitor 50 includes a capacitor main body 51 and a pair of front and rear lead wires 52F and 52R extending from the capacitor main body 51. The capacitor main body 51 has a substantially rectangular shape when viewed from the side, and the width dimension is smaller than the front-rear dimension and the vertical dimension. The capacitor 50 is disposed in the box-shaped member 12 in a state where the capacitor main body 51 is accommodated in the accommodating portion 17. The capacitor main body 51 can move in the front-rear direction and the left-right direction in the housing portion 17 in order to absorb the positional deviation between the connection portion 44 and the lead wire 52R and the positional deviation between the welding portion 32 and the lead wire 52F. ing.

  Each of the pair of lead wires 52F and 52R is led upward from the front end portion and the rear end portion on the upper surface of the capacitor main body 51. The front lead wire 52F led upward is bent so as to turn forward, and its tip is connected to the rear surface of the welded portion 32 of the terminal fitting 30 by solder 62 (welding). Further, the rear lead wire 52R led out upward is turned rearward, and the front end portion thereof is connected to the front surface of the connection portion 44 of the ground member 40 by solder 62 (welding).

<Coil 60>
The coil 60 is configured to be spirally wound around the outer periphery of a cylindrical core 61 whose axis is directed in the front-rear direction. The coil 60 is mounted on the upper surface of the bottom wall portion 13, and the core 61 is supported between the pair of front and rear clamping portions 16 so that the movement is restricted with respect to the box-shaped member 12. ing.

  Both ends of the coil 60 are connected to the welded portions 32 of the pair of terminal fittings 30 by solder 62 (welding). The welding of the coil 60 is performed simultaneously in the process of welding the lead wire 52F on the front side of the capacitor 50. As described above, the coil 60 and the two capacitors 50 connected to the ground member 40 and the terminal fitting 30 constitute a π-type filter circuit, and effectively reduce the noise of the circuit of the wire harness connected to the terminal fitting 30. It functions as a filter to be removed.

<Operation and Effect of Example 1>
The manufacturing process of the noise filter will be described. First, the housing 10 and the pair of terminal fittings 30 are integrated at the same time as the housing 10 is formed by insert molding. Next, with the opening 15 of the box-shaped member 12 facing upward, the coil 60 is accommodated in the box-shaped member 12 and positioned and held by the clamping unit 16, and the capacitor 50 is held in the box-shaped member 12. And set in the accommodating portion 17.

  When the coil 60 and the capacitor 50 are accommodated in the box-shaped member 12, the ground member 40 is assembled to the box-shaped member 12 (housing 10), and the opening 15 is closed with the plate-shaped main body 41. Thereafter, in the box-shaped member 12, welding of the coil 60 and the terminal fitting 30, welding of the front lead wire 52F and the terminal fitting 30, and welding of the rear lead wire 52R and the ground member 40 are performed.

  The welded portion 32 of the terminal fitting 30 is disposed at an upper end portion in the box-shaped member 12, that is, a position close to the opening portion 15. A window formed in the plate-like main body portion 41 is located above the welded portion 32. A hole 48 is opened. Through the window hole 48, the welded region of the welded portion 32 is exposed to the upper outside of the box-shaped member 12. Welding of the coil 60 and the front lead wire 52F to the welded portion 32 in the box-shaped member 12 is performed by inserting a soldering iron (not shown) into the window hole 48 from above the box-shaped member 12.

  At this time, there is a concern that the peripheral wall portion 14 (opening edge of the opening portion 15) is thermally deformed by the high temperature soldering iron coming into contact with the peripheral wall portion 14 made of synthetic resin. However, since the window hole 48 is closed over the entire circumference, even if the soldering iron moves back and forth and right and left, it only hits the hole edge of the window hole 48 and there is no possibility of contacting the peripheral wall portion 14.

  Further, the connection portion 44 of the ground member 40 is also arranged at the upper end portion in the box-shaped member 12, that is, at a position close to the opening portion 15, similarly to the weld portion 32. A notch 47 formed in the plate-like main body 41 is opened near the upper portion of the connecting portion 44. By this cutout portion 47, the welding region of the connection portion 44 is exposed to the upper outside of the box-shaped member 12. Therefore, in the welding of the rear lead wire 52R to the connecting portion 44 in the box-shaped member 12, a soldering iron (not shown) is inserted into the cutout portion 47 from above the box-shaped member 12 in the same manner as the welding of the welded portion 32. Do it.

  At this time, there is a concern that the peripheral wall portion 14 (opening edge of the opening portion 15) is thermally deformed by the high temperature soldering iron coming into contact with the peripheral wall portion 14 made of synthetic resin. However, the notch 47 is closed over the entire circumference, and the connecting portion 44 is located at the rear edge of the opening edge of the notch 47. Therefore, even if the soldering iron moves back and forth and right and left, it only hits the opening edge of the notch 47 and the connecting portion 44, and there is no possibility of contacting the peripheral wall portion 14.

  The noise filter of the first embodiment includes a box-shaped member 12 made of synthetic resin having an opening 15, a plate-like main body 41 arranged so as to close the opening 15, and a box-shaped member from the plate-like main body 41. 12 and a metal grounding member 40 having a connecting portion 44 that protrudes toward the inside of the housing 12. A capacitor 50 is accommodated in the box-shaped member 12, and a lead wire 52 </ b> R provided on the capacitor 50 is connected to the connection portion 44 in the box-shaped member 12 by welding. The plate-like main body 41 is formed with a notch 47 that exposes a welding region between the connecting portion 44 and the lead wire 52 </ b> R to the outside of the box-shaped member 12.

  According to this configuration, the connection portion 44 and the lead wire 52 </ b> R can be connected by welding through the cutout portion 47 from the outside of the box-shaped member 12. Since the cutout portion 47 and the connection portion 44 to be welded are formed on the same plate-like main body portion 41, the projecting dimension of the connection portion 44 from the plate-like main body portion 41 is reduced, and the ground member 40 Material cost reduction has been realized.

  In addition, since the noise filter is formed by the cutout portion 47 cutting out the connection portion 44, the portion removed from the plate-like main body portion 41 to form the cutout portion 47 is used as the connection portion 44. ing. Therefore, the material cost can be further reduced, and the connection portion 44 can be disposed in the vicinity of the notch portion 47. Further, although the connection portion 44 is disposed in the vicinity of the opening edge of the opening portion 15, the welding region with the lead wire 52 </ b> R in the connection portion 44 faces the side opposite to the opening edge of the opening portion 15. Therefore, the influence of heat on the opening edge of the opening 15 is reduced during welding.

<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 Example 1 described above, the cutout portion is formed by raising the connection portion. However, the connection portion may be formed separately from the portion removed to form the cutout portion.
(2) In the first embodiment, the cutout portion has a window shape that is closed over the entire circumference. However, the cutout portion may be open to the outer peripheral edge of the plate-like main body portion.
(3) In the first embodiment, a π-type filter circuit is configured by two capacitors and one coil. However, in the present invention, the filter circuit is configured by one capacitor and one coil. It can also be applied to the case of being composed of one capacitor or the case of being composed of two capacitors.
(4) In the first embodiment, the connection means to the noise removal target circuit is a connector structure by the hood formed on the box-shaped member, but the connection means to the noise removal target circuit constitutes the noise removal target circuit. A structure such as assembling a terminal fitting fixed to an electric wire to be attached to a box-shaped member may be used.
(5) In the first embodiment, the grounding portion formed on the ground member is arranged so as to protrude rearward from the terminal fitting with the filter element sandwiched in the front-rear direction. However, the grounding portion should be formed on the grounding member. Alternatively, an earth terminal provided on the earth member may be arranged in line with the terminal fitting, and the earth terminal and the earth member may be connected.

DESCRIPTION OF SYMBOLS 12 ... Box-shaped member 15 ... Opening part 40 ... Grounding member 41 ... Plate-shaped main-body part 44 ... Connection part 47 ... Notch part 50 ... Capacitor 52R ... Lead wire

Claims (3)

A synthetic resin box-shaped member having an opening;
A metal earth member attached to the box-shaped member so as to have a plate-like main body portion and close the opening with the plate-like main body portion;
Formed in a form protruding on the plate-shaped main body, and connected to the inside of the box-shaped member in a state where the grounding member is assembled to the box-shaped member;
A capacitor housed in the box-shaped member;
A lead wire provided in the capacitor and connected to the connecting portion by welding in the box-shaped member;
A noise filter, comprising: a notch portion formed in the plate-like main body portion and exposing a welding region between the connection portion and the lead wire to the outside of the box-shaped member.   The noise filter according to claim 1, wherein the cutout portion is formed by cutting up the connection portion. The connecting portion is disposed in the vicinity of the opening edge of the opening,
3. The noise filter according to claim 1, wherein a welding region of the connection portion with the lead wire faces an opposite side of the opening edge of the opening.

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