Noise filter

Abstract

To provide a noise filter to and from which a capacitor can be easily attached and detached.SOLUTION: A noise filter 1 to be equipped on an automobile comprises: a base 5; a terminal 3 and brackets 4a, 4b held on the base 5; a capacitor 2 electrically connected to the terminal 3 and the brackets 4a, 4b; and a cover 6 which is provided in a manner attachable / detachable to and from the base 5, and which is fitted to the base 5 so as to cover the capacitor 2. The terminal 3 has an insertion part 31 into which one of terminal parts 26 of the capacitor 2 is inserted, and which is electrically connected to the terminal part 26. The bracket 4a, 4b have an insertion part 44 into which the other one of the terminal parts 26 of the capacitor 2 is inserted, and which is electrically connected to the terminal part 26. The capacitor 2 is provided in such a manner that it can be inserted into and removed from the insertion part 31 of the terminal 3 and the insertion part 44 of the brackets 4a, 4b.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a noise filter. [Background technology]

[0002] Noise filters that reduce electrical noise carried in electric circuits are known. As an example of a noise filter, Patent Document 1 discloses a noise filter including a ground conductor that is grounded to a vehicle body panel, a first conductor that is connected to an electric wire of a wire harness, a capacitor, and a housing that houses these. The capacitor has a pair of lead terminals, one of which is welded to the ground conductor and the other of which is welded to the first conductor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-208487 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above noise filter has a structure in which the lead terminals of the capacitor are welded to the ground conductor and the first conductor, and therefore has the problem that it is difficult to remove or replace the capacitor.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a noise filter that allows a capacitor to be easily attached and detached. [Means for solving the problem]

[0006] The present invention is a noise filter comprising a base, a terminal and a bracket held by the base, a capacitor electrically connected to the terminal and the bracket, and a cover that is removably provided on the base and attached to the base to cover the capacitor, wherein the capacitor has a pair of plate-shaped terminal portions, the terminal has an insertion portion into which one terminal portion of the capacitor is inserted and electrically connected to the terminal portion, the bracket has an insertion portion into which the other terminal portion of the capacitor is inserted and electrically connected to the terminal portion, and the capacitor is arranged to be insertable and removable into the insertion portion of the terminal and the insertion portion of the bracket. Effect of the Invention

[0007] According to the present invention, the capacitor is removably provided in the terminal insertion portion and the bracket insertion portion, and therefore can be easily attached and detached. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing a noise filter according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing the rear side of the noise filter in FIG. [Diagram 3] 2 is a diagram showing the bottom side of the noise filter in FIG. 1. [Figure 4] FIG. 2 is an exploded view of the noise filter of FIG. [Diagram 5] FIG. 2 is a diagram showing the noise filter in FIG. 1 with the cover removed. [Figure 6] FIG. 6 is a diagram showing a state in which the capacitor in FIG. 5 is removed. [Figure 7] FIG. 5 is a diagram showing only the capacitor in FIG. 4. [Figure 8] FIG. 8 is an exploded view of the capacitor of FIG. [Figure 9] FIG. 3 shows only the cover of FIG. 2. [Figure 10] FIG. 5 is a diagram showing the upper surface side of the base in FIG. [Figure 11]5 is an explanatory diagram illustrating an electrical connection structure between the capacitor, the terminal, and the bracket in FIG. 4. [Figure 12] FIG. 2 is a diagram showing an automobile equipped with the noise filter of FIG. 1. [Figure 13] This is a noise removal circuit configured by the noise filter in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A "noise filter" according to one embodiment of the present invention will be described with reference to FIGS.

[0010] The noise filter 1 in this example is a noise filter for AM radio, and is installed in an automobile 10 as shown in Fig. 12 to form, for example, a noise removal circuit as shown in Fig. 13. In Fig. 12, reference numeral 11 denotes a body panel, reference numeral 12 denotes an AM radio antenna, reference numeral 13 denotes a rear window defogger, reference numeral 14 denotes a high-mounted stop lamp, and dashed arrow N denotes noise. Reference numeral 7 denotes a branch line branched off from the main line of the wire harness, and is electrically connected to the noise filter 1.

[0011] As shown in Figure 12, AM radio antenna 12 is close to rear window defogger 13 and is affected by noise N, but is far enough away from high mounted stop lamp 14 that it is not affected by noise N. In addition to the above, other noise sources that can affect AM radio antenna 12 include luggage room lamps, etc.

[0012] The noise filter 1 is provided for each noise source and is attached to the middle of the circuit going to the noise source. The noise filter 1 is fixed to the vehicle body panel 11 with a bolt and is thereby grounded to the vehicle body panel 11.

[0013] For example, as shown in FIGS. 12 and 13, the noise filter 1 is connected to an electric wire (branch wire 7) that electrically connects an ECU (Electronic Control Unit) 15 and a rear window defogger 13, and filters out noise on the electric wire to the vehicle body panel 11 side.

[0014] 1 to 5, the noise filter 1 includes a base 5, a pair of terminals 3 and a pair of brackets 4a, 4b held by the base 5, a pair of capacitors 2, and a cover 6. The noise filter 1 of this example is designed to be connectable to two circuits, and thus includes a pair of terminals 3, brackets 4a, 4b, and capacitor 2, but it is sufficient to include at least one of each of these.

[0015] The base 5 is made of insulating synthetic resin. As shown in Figs. 3, 4 and 10, the base 5 has a block-shaped base body 51, a peripheral wall 52 standing in a rectangular tubular shape from an upper surface 51a of the base body 51, and a locking portion 55 and a pair of locking projections 56 provided on the outer surface of the peripheral wall 52.

[0016] The base body 51 has an upper surface 51a formed with mounting grooves 53 for the pair of terminals 3 and mounting grooves 54 for the pair of brackets 4a, 4b. The base body 51 has four recesses 57 (two pairs for two circuits) recessed from the lower surface 51b. The outer conductor connection portion 32 of the terminal 3 is disposed in each of the recesses 57.

[0017] The designations indicating directions such as "upper surface 51a" and "lower surface 51b" are given for the convenience of explanation in this specification, and do not necessarily correspond to the actual up-down direction when the noise filter 1 is installed in the automobile 10.

[0018] The locking portion 55 is a portion that is locked into a locking hole of the vehicle body panel 11. The pair of locking projections 56 is a portion that is locked into a pair of locking recesses 66 of the cover 6.

[0019] The pair of terminals 3 are obtained by pressing a metal plate or the like. That is, the pair of terminals 3 are composed of a single metal plate. The pair of terminals 3 used have the same shape and size. Each terminal 3 has an insertion portion 31 into which one terminal portion 26 of the capacitor 2 is inserted and electrically connected to the terminal portion 26, a pair of outer conductor connecting portions 32, and a connecting portion 33 connecting these portions.

[0020] The insertion part 31 is formed into a square tube shape by winding a metal plate in a spiral shape and bending it six times at right angles. The insertion part 31 can receive the terminal part 26 in the inner space, and has a spring property because the inner end is a free end. The insertion part 31 and the connecting part 33 are arranged in the mounting groove 53 of the base body 51 (i.e., on the upper surface 51a side of the base body 51).

[0021] The pair of external conductor connecting portions 32 extend in a plate shape from the band-shaped coupling portion 33. As described above, these external conductor connecting portions 32 are disposed in the recesses 57 of the base body 51 (i.e., on the lower surface 51b side of the base body 51). One external conductor connecting portion 32 is disposed in one recess 57.

[0022] A female terminal is connected to the branch wire 7 branched off from the trunk wire of the above-mentioned wire harness, and this female terminal is positioned in the recess 57 and is male-female fitted with the outer conductor connecting portion 32. In this way, the noise filter 1 is electrically connected to the branch wire 7.

[0023] The pair of brackets 4a, 4b are obtained by performing press processing on a metal plate. That is, the pair of brackets 4a, 4b are composed of a single metal plate. These brackets 4a, 4b have the same function, but some dimensions are different due to layout reasons. The brackets 4a, 4b have an insertion part 44 into which the other terminal part 26 of the capacitor 2 is inserted and electrically connected to the terminal part 26, a ground part 41, an extension part 43 extended from the ground part 41, and band-shaped connecting parts 45a, 45b connecting the extension part 43 and the insertion part 44.

[0024] The insertion portion 44 is formed into a square tube shape by winding a metal plate in a spiral shape and bending it at right angles five times. The insertion portion 44 can receive the terminal portion 26 in the inner space, and has a spring property because the inner end is a free end. The insertion portion 44 and the connecting portions 45a, 45b are arranged in the mounting groove 54 of the base main body 51 (i.e., on the upper surface 51a side of the base main body 51). The lower half of the extension portion 43 is arranged in the mounting groove 54, and the upper half is arranged in the peripheral wall 52.

[0025] The grounding portion 41 is formed in a flat plate shape and has a bolt insertion hole 42 formed therein. The grounding portion 41 is disposed above the peripheral wall 52 and disposed outside the base 5. The grounding portion 41 is placed on the vehicle body panel 11 and fastened to the vehicle body panel 11 by the bolt 8. As a result, the noise filter 1 is fixed to the vehicle body panel 11 and is grounded (body earthed).

[0026] In this example, as shown in Fig. 11, brackets 4a, 4b are stacked on top of each other and held by base 5. The grounding portions 41 and the extension portions 43 are all stacked on top of each other, but the insertion portions 44 cannot be stacked on top of each other and are therefore positioned at offset positions. In order to position the insertion portions 44 in this manner, the lengths of connecting portions 45a, 45b are different. In detail, connecting portion 45a, which is positioned inside connecting portion 45b, is formed shorter than connecting portion 45b.

[0027] The pair of capacitors 2 have the same shape and size. As shown in Figures 7 and 8, each capacitor 2 has a capacitor element 20, a pair of metal parts 23, and a molded part 27 that integrates these.

[0028] Capacitor element 20 has a capacitor body 21 and a pair of lead terminals 22. A pair of metal parts 23 are obtained by subjecting a metal plate to press working or the like, and have the same shape and size.

[0029] Each metal part 23 has an L-shaped portion 24 aligned along a corner of the capacitor body 21, an elongated plate-shaped terminal portion 26 extending from one end of the L-shaped portion 24, and a plate-shaped welded portion 25 provided at the boundary between the L-shaped portion 24 and the terminal portion 26.

[0030] Lead terminals 22 of capacitor element 20 are overlapped and welded to welded portion 25 of metal part 23. Molded portion 27 is made of insulating synthetic resin, and molds the periphery of capacitor body 21 and L-shaped portion 24 of the pair of metal parts 23. Instead of this molded portion 27, a resin case that covers the periphery of capacitor body 21 and L-shaped portion 24 of the pair of metal parts 23 may be used.

[0031] In this way, capacitor 2 is formed in a cassette type that can be inserted and removed into insertion portion 31 of terminal 3 and insertion portions 44 of brackets 4a and 4b. That is, the electrical connection structure between terminal portion 26 of capacitor 2 and insertion portions 31 and 44 is a male-female fitting structure that is not welded, so that even a person without special skills can easily attach and detach capacitor 2.

[0032] The cover 6 is made of insulating synthetic resin. As shown in FIG. 9, the cover 6 is formed in a box shape having an upper wall 61, a front wall 62, a rear wall 63, and side walls 64, 65. The cover 6 is placed on the outer surface of the peripheral wall 52 of the base 5 to cover the capacitor 2. The inner surfaces of the side walls 64, 65 are formed with locking recesses 66 that lock onto the locking protrusions 56 of the base 5. The rear wall 63 is formed with a cutout portion 67 for exposing the locking portion 55 and the ground portion 41 of the base 5. In this manner, the cover 6 is provided detachably on the base 5.

[0033] The noise filter 1 configured as above is delivered with the pair of terminals 3 and the pair of brackets 4a, 4b held by the base 5, the cover 6 attached to the base 5, and the grounding portion 41 bolted to the vehicle body panel 11. It is of course possible for the capacitor 2 to be delivered in a state where it is attached to the base 5, but it is also possible for it to be delivered in an unattached state as shown in Fig. 6. Even in this case, it is preferable that the cover 6 is attached.

[0034] Nowadays, the price of automobiles is soaring, and it would be ideal if buyers could freely choose their vehicle equipment, rather than purchasing vehicle equipment unintentionally. Conventional noise filters were installed as standard equipment in vehicles along with the AM radio itself, and vehicle buyers had no choice but to purchase them. However, AM radio is on the decline these days, and AM broadcasting has switched to Internet broadcasting and FM synchronous broadcasting, and it is thought that AM radio will soon become a dealer option rather than a standard equipment. With the shift to dealer options, it is expected that AM radios will be able to be retrofitted by dealers, but conventional noise filters are expected to remain standard equipment. The reason for this is that, as mentioned above, conventional noise filters are one-piece, non-disassembled structures, making them difficult for dealers or users to install.

[0035] In contrast, the noise filter 1 of this embodiment can be installed by the dealer or the user individually, not only at the time of delivery of the vehicle, but also after delivery. However, it is preferable that the parts other than the capacitor 2 are standard parts, taking into consideration the ease of maintenance, such as the conductivity of the grounding part 41. Even in such a case, since the capacitor 2, which is the most expensive of the components of the noise filter 1, can be installed later, the price can be kept low if one chooses not to install the capacitor 2. Furthermore, when installing the capacitor 2, it is not necessary to remove the bolts 8 that secure the grounding part 41 of the noise filter 1, and the cover 6 can be removed and the capacitor 2 can be attached to the base 5 while the noise filter 1 is still fixed to the vehicle body panel 11.

[0036] In this way, according to the present invention, the capacitor 2 of the noise filter 1 can be selected as an accessory that can be retrofitted. When a vehicle purchaser deems the noise filter 1 unnecessary, the vehicle purchase price can be optimized by not installing the capacitor 2. Furthermore, a vehicle purchaser can retrofit the capacitor 2 when necessary even when the vehicle is complete, such as when changing their mind after delivery or when purchasing a used car.

[0037] In the above-described embodiment, a noise filter for AM radio has been described. However, the use of the noise filter of the present invention is not limited to removing noise from AM radio, and the noise filter can be applied to various electronic devices.

[0038] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be embodied in various modifications without departing from the gist of the present invention. As long as the configuration of the present invention is still provided even with such modifications, it is of course included in the scope of the present invention. [Explanation of symbols]

[0039] 1. Noise Filter 2. Capacitor 3 Terminal 4a,4b Bracket 5. Bass 6 Cover 26 Terminal section 31 Insertion section 32 Outer conductor connection 41 Grounding part 44 Insertion section

Claims

1. With the base, a terminal and a bracket held by the base; a capacitor electrically connected to the terminal and the bracket; a cover that is detachably provided on the base and attached to the base to cover the capacitor; The capacitor has a pair of plate-shaped terminal portions, the terminal has an insertion portion into which one terminal portion of the capacitor is inserted to be electrically connected to the terminal portion, the bracket has an insertion portion into which the other terminal portion of the capacitor is inserted to be electrically connected to the terminal portion, The capacitor is removably provided in the terminal insertion portion and the bracket insertion portion. A noise filter characterized by:

2. The bracket is made of a single metal plate and has the insertion portion bent into a square tube shape and a grounding portion formed into a flat plate shape and having a bolt insertion hole.

2. The noise filter according to claim 1.

3. The terminal is made of a single metal plate and has the insertion portion bent into a rectangular tube shape and a pair of outer conductor connection portions formed into plate shapes.

2. The noise filter according to claim 1.

4. The terminal insertion portion and the bracket insertion portion are disposed on an upper surface side of the base, The pair of outer conductor connecting portions are disposed on the lower surface side of the base.

4. The noise filter according to claim 3.

5. The base has a pair of recesses formed in a lower surface thereof, and the outer conductor connecting portions are disposed in the respective recesses.

5. The noise filter according to claim 4.

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