JP4946493B2 - Film capacitor - Google Patents

Description

  The present invention relates to a film capacitor, and more particularly, to a film capacitor of a type in which a capacitor element is housed in a case, which is used for electrical equipment of automobiles.

A conventional film capacitor uses a polymer film such as polyethylene terephthalate or polypropylene film as a dielectric film, and a capacitor element in which a metallized film in which a metal electrode is formed on the surface by vacuum deposition or the like is wound or laminated with a resin. There are a packaged type and a type in which a capacitor element is accommodated in a case and a gap between the capacitor element and the case is filled with resin as described in Patent Document 1. However, for applications where the usage environment such as automobile electrical equipment becomes high humidity, it is easy to select a resin that has a high effect of suppressing the ingress of moisture into the resin to be filled, and the latter type in which the capacitor element is housed in a case. Mainly used.
Japanese Patent Laid-Open No. 02-270315

  Conventionally, a capacitor type in which a capacitor element is housed in a case and filled with resin has a smaller specific gravity than the liquid resin in which the specific gravity of the capacitor element is filled. When filling and filling the capacitor element, the capacitor element floats and the thickness of the resin covering the upper part of the capacitor element is partially reduced. As a result, moisture easily enters the capacitor element in the thinned portion. There was a problem that the moisture resistance performance of the capacitor deteriorated.

  Therefore, the film capacitor of the present invention has a structure in which the capacitor element does not float when the resin is injected and filled into the case containing the capacitor element, so that the resin covering the capacitor element is not partially thinned, thereby The purpose is to ensure the moisture resistance of the capacitor.

In order to achieve this object, the film capacitor of the present invention is connected to a collective electrode of a capacitor element housed in a case, and a plurality of conductive wires connected outside the upper opening of the case are connected in series. The upper part of the connection part of these several conductors is made to contact | abut to the lower surface of the convex part provided in the inner wall surface of the case.

As described above, the conductive wire connected to the capacitor element is constituted by a plurality of conductors connected in series, and the upper part of the connection portion of the plurality of conductors is formed on the lower surface of the convex portion provided on the inner wall surface of the case. Since the contact is made, the rise of the capacitor element at the time of resin injection caused by the difference in specific gravity between the capacitor element and the resin is suppressed. As a result, the thickness of the resin covering the upper part of the capacitor element is not reduced, and the film capacitor It is possible to ensure the moisture resistance.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the film capacitor of the present embodiment includes a bottomed case 1 having convex portions 10 and 11 provided on two inner wall surfaces facing each other and an open top surface, and the inside of the case 1 The capacitor element 2 housed in the capacitor element 2 and the conductive wires 7 and 8 provided with the projections 5 and 6 and connected to the collective electrodes 3 and 4 provided on the pair of side surfaces of the capacitor element 2 and the capacitor element 2 and the resin 9 filled so as to be filled in, these constituent bodies will be described in order below.

  First, the case 1 is made of polybutylene terephthalate resin. The lower surfaces of the protrusions 10 and 11 are provided with protrusions of 5 mm at positions substantially the same as the upper portions of the protrusions 5 and 6 provided on the conductive wires 7 and 8 of the capacitor element 2 in the state of being accommodated in the case 1. It has been.

  The shape of the protrusions 10 and 11 is such that the upper surface of the protrusions 10 and 11 is perpendicular to the inner wall surface of the case 1, and the lower surface of the protrusions 10 and 11 is from the end of the upper surface of the protrusions 10 and 11. The conductive wire 7 of the capacitor element 2 is in a state in which it is an inverted triangle inclined toward the inner wall surface of the case 1 and the substantially central portion in the vertical direction of the lower surface where the convex portions 10 and 11 are inclined is housed in the case 1. , 8 so as to be at the same height as the upper portions of the protrusions 5, 6. Thus, if it is made the shape which inclined the lower surface of the convex parts 10 and 11, the space | interval of the protrusion part 5 of the conductive wire 7 of the capacitor | condenser element 2 to accommodate and the protrusion part 6 of the conductive wire 8 is made into the convex part 10, The position or set of the protrusions 5 and 6 formed on the conductive wires 7 and 8 simply by bending the conductive wires 7 and 8 outward so that the distance between the pair of inner wall surfaces provided with 11 is wider. Even if the connection positions of the conductive wires 7 and 8 to the electrodes 3 and 4 are slightly shifted in the vertical direction, the upper portions of the protrusions 5 and 6 are reliably provided on the inner wall surface of the case 1 by the spring property of the conductive wires 7 and 8. It is possible to come into contact with the lower surfaces of the convex portions 10 and 11.

  Next, as shown in FIG. 5 and FIG. 6, the capacitor element 2 is formed by stacking two metallized films 21 formed by vacuum deposition of aluminum electrodes 20 on the surface of a polyethylene terephthalate film having a thickness of 5 μm as a polymer film. The cylindrical shape is wound, and this cylindrical shape is pressed to form an elliptical columnar wound body 23 as shown in FIG.

  As shown in FIG. 5, the electrode 20 is continuously formed in the longitudinal direction on the surface of the metallized film 21, but on the upper side in FIG. Are continuously formed in the longitudinal direction.

  In addition, when winding in the state which piled up two such metallized films 21, the margin 22 formed continuously in the longitudinal direction of the two metallized films 21 is the width direction orthogonal to a longitudinal direction (A direction in FIG. 5) are opposite to each other, and are further shifted in the width direction (0.3 to 0.8 mm in this embodiment).

  Next, as shown in FIG. 7, a plurality of metal components including zinc, tin, and copper are sprayed on the pair of side surfaces of the capacitor element 2 wound in this way to form the collective electrodes 3 and 4. Yes.

  On the side surfaces of the collecting electrodes 3 and 4, the lower ends of the conductive wires 7 and 8 made of a single metal wire made of a tin-plated copper-coated steel wire having a diameter of 1 mm and provided with protrusions 5 and 6 by crushing a part thereof. The portion is connected to the capacitor element 2 by solders 12 and 13 (not shown in FIG. 7). The specific gravity of the capacitor element 2 at this time is about 1.3.

  The connection positions of the conductive wires 7 and 8 to the collective electrodes 3 and 4 are substantially the center in the left-right direction of the collective electrodes 3 and 4 in a state where the capacitor element 2 is housed in the case 1. Lower than the center of direction. This is because the conductive wires 7 and 8 are bent outward to ensure that the upper portions of the protrusions 5 and 6 of the conductive wires 7 and 8 are in contact with the inclined lower surfaces of the convex portions 10 and 11 of the case 1. Thus, when the interval between the protrusion 5 provided on the conductive wire 7 and the protrusion 6 provided on the conductive wire 8 is widened, the solder 12 and 13 between the conductive wires 7 and 8 and the collective electrodes 3 and 4 are used. This is to increase the width of the connection while reducing the stress load on the connecting portion as much as possible. As a result, the upper portions of the protrusions 5 and 6 provided on the conductive wires 7 and 8 are provided on the case 1 so that the reliability of the connection between the collective electrodes 3 and 4 and the conductive wires 7 and 8 is not impaired. The lower surfaces of the portions 10 and 11 can be reliably brought into contact with each other.

  The capacitor element 2 created in this way was stored such that the lower surface of the capacitor element 2 was in contact with the inner bottom surface of the case 1. At this time, the upper portions of the protrusions 5 and 6 provided on the conductive wires 7 and 8 are in contact with the lower surfaces of the protrusions 10 and 11 of the case 1.

  Next, after filling and filling the case 1 with a liquid thermosetting resin 9 having a specific gravity of approximately 1.6 and containing epoxy resin and a filler material as main components, the case 1 is filled at a high temperature of 80 ° C. to 125 ° C. The resin 9 is cured by leaving it in the atmosphere for 4 hours.

  In the film capacitor of the present embodiment created as described above, the protrusions 5 and 6 are provided on a part of the conductive wires 7 and 8 connected to the capacitor element 2, and the upper portions of the protrusions 5 and 6 are formed on the case. 1 is made to abut on the lower surfaces of the convex portions 10 and 11 provided on the inner wall surface 1, and the abutted portion is caused by the difference in specific gravity between the capacitor element 2 and the resin 9 when the resin 9 is injected and filled. The floating of the capacitor element 2 can be suppressed, and the thickness of the resin 9 covering the capacitor element 2 is not partially reduced. As a result, the moisture resistance of the film capacitor can be ensured.

  In addition, as a method of providing the protruding portions 5 and 6 on the conductive wires 7 and 8, there are methods such as attaching a small piece of another conductive wire with solder or bending a part of the conductive wires 7 and 8. As described above, if a single metal wire is used for the conductive wires 7 and 8 and a part of the conductive wires 7 and 8 is crushed, the protrusions 5 and 6 can be easily and reliably provided.

  In the present embodiment, the shape of the convex portions 10 and 11 is such that the upper surface of the convex portions 10 and 11 is perpendicular to the inner wall surface of the case 1, and the lower surface of the convex portions 10 and 11 is the upper end of the convex portions 10 and 11. Inverted triangles inclined toward the inner wall surface of the case 1 from the portion, and the conductive wires 7 and 8 are bent outward, and the protrusions 5 provided on the conductive wires 7 and the protrusions provided on the conductive wires 8 The interval between the portions 6 is made larger than the interval between the pair of inner wall surfaces on which the convex portions 10 and 11 of the case 1 are provided. However, the present invention is not limited to these. The protrusion 5 provided on the conductive wire 7 and the protrusion 6 provided on the conductive wire 8 are formed such that the upper surface of the conductive wire 7 is perpendicular to the inner wall surface of the case 1 and the lower surface is parallel to the upper surfaces of the protrusions 10 and 11. Even if the interval is not larger than the interval between the pair of inner wall surfaces provided with the convex portions 10 and 11 of the case 1, Top of the protrusion 5 and 6 on the lower surface of the 10, 11 may, if the dimensional relationship abutting. In this case, the capacitor element 2 is accommodated in the case 1 when the positions where the protrusions 5 and 6 are formed on the conductive wires 7 and 8 and the connection positions of the conductive wires 7 and 8 to the collective electrodes 3 and 4 are shifted upward. However, the effect of suppressing the floating of the capacitor element 2 is not impaired. If the capacitor element 2 is housed in the case 1, the upper portions of the protrusions 5 and 6 may not come into contact with the lower surfaces of the projections 10 and 11 when the resin 9 is injected and filled. The capacitor element 2 is slightly lifted, and by this floating, the upper portions of the protrusions 5 and 6 are brought into contact with the lower surfaces of the projections 10 and 11, and further floating can be suppressed.

(Embodiment 2)
Embodiment 2 of the present invention will be described below with reference to the drawings.

  FIG. 2 is a cross-sectional view of the case 1 in which the capacitor element 2 is housed in the case 1 of the present embodiment.

  In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The difference between the present embodiment and the first embodiment is that the protrusions 5 and 6 provided on the conductive wires 7 and 8 are connected to the conductors 16 and 17 and the connection points 24 and 25 between 18 and 19. It is that. Specifically, the conductors 16 and 18 made of a single metal wire made of a tin-plated copper-clad steel wire having a diameter of 1 mm are connected to the conductors 17 and 19 of a coated stranded wire having a cross-sectional area of 2 mm ² as connection portions 24 and 25. The coverings of the portions are peeled off and connected by soldering, and the overlapping portions of the conductors 16 and 18 and the connecting portions 24 and 25 formed by the overlapping of the conductors 17 and 19 and the solder are the protruding portions 5 and 6.

  In the present embodiment created as described above, the upper portions of the protrusions 5 and 6 provided on the conductive wires 7 and 8 are brought into contact with the lower surfaces of the protrusions 10 and 11 provided on the inner wall surface of the case 1. By doing so, it is possible to suppress the floating of the capacitor element 2 when the resin 9 is injected and filled, so that the resin 9 covering the capacitor element 2 is not partially thinned, and the moisture resistance of the film capacitor can be secured. A step of providing protrusions 5 and 6 on the conductive wires 7 and 8 when the specifications of the conductors 16 and 18 connected to the collecting electrodes 3 and 4 and the conductors 17 and 19 connecting the film capacitors to the circuit are different; Since the process of connecting the conductors 16, 18 and 17, 19 having different specifications is completed in one process, productivity is improved.

(Embodiment 3)
Embodiment 3 of the present invention will be described below with reference to the drawings.

  FIG. 3 is a plan view of the case 1 of the present embodiment, and FIG. 4 is a perspective view of the case 1 in which the capacitor element 2 is housed in the case 1 of the present embodiment.

  In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between the present embodiment and the first embodiment is that groove portions 14 and 15 are provided at the tips of the convex portions 10 and 11 provided on the inner wall surface of the case 1, and the conductive wires 7 and 15 are provided in the groove portions 14 and 15. 8 is housed.

  The details of the groove portions 14 and 15 are provided in a substantially semicircular shape with a radius of 0.6 mm at a substantially central portion in the width direction of the convex portions 10 and 11 from the upper surface end to the lower surface end of the convex portions 10 and 11. ing.

  In the present embodiment created as described above, the upper portions of the protrusions 5 and 6 provided on the conductive wires 7 and 8 are brought into contact with the lower surfaces of the protrusions 10 and 11 provided on the inner wall surface of the case 1. By doing so, the floating of the capacitor element 2 during the filling and filling of the resin 9 is suppressed, and part of the conductive wires 7 and 8 are accommodated in the grooves 14 and 15, so that the conductive wires 7 and 8 are provided. The upper portions of the protruding portions 5 and 6 (not shown in FIG. 4) can be easily and reliably brought into contact with the lower surfaces of the convex portions 10 and 11 provided on the inner wall surface of the case 1. Capacitor element facing the pair of inner wall surfaces not provided with the convex portions 10, 11 because movement toward the pair of inner wall surfaces not provided with the convex portions 10, 11 is suppressed in the case 1. The thickness of the resin 9 covering the side surfaces of the film 2 is not reduced, Decrease in moisture resistance of the capacitors is further suppressed.

  In the present embodiment, the shape of the groove 14 is a substantially semicircular shape with a cross section of a radius of 0.6 mm. However, the shape is not limited to this shape as long as part of the conductive wires 7 and 8 can be accommodated.

  As described above, the film capacitor of the present invention has a structure that suppresses the floating of the capacitor element when the resin is injected, and the thickness of the resin covering the capacitor element is not partially reduced, thereby ensuring moisture resistance. It can be used for electronic and electrical equipment in a wide range of fields including automotive electrical equipment.

Sectional drawing of the film capacitor in Embodiment 1 of this invention Sectional drawing of the film capacitor in Embodiment 2 of this invention The top view of the case in Embodiment 3 of this invention The perspective view of the film capacitor in Embodiment 3 of this invention The top view of the metallized film in Embodiment 1 of this invention The perspective view of the wound body in Embodiment 1 of this invention The perspective view of the capacitor | condenser element in Embodiment 1 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Capacitor element 3, 4 Collective electrode 5, 6 Protruding part 7, 8 Conductive wire 9 Filling resin 10, 11 Protruding part 14, 15 Groove part 16, 17 Conductor 18, 19 Conductor 24, 25 Connection location

Claims (2)

A bottomed case, a capacitor element stored horizontally in the case, and a resin filled in the case so as to fill the capacitor element, a pair of collecting electrodes on the side surface of the capacitor element the inner wall is to connect the conductive wire drawn in the upper surface opening portion outside of the case while being composed of a plurality of conductors connected in series, facing the collection electrode of the capacitor element before Symbol case The film capacitor is characterized in that a convex portion is provided, and upper portions of connection portions of the plurality of conductors constituting the conductive wire are brought into contact with a lower surface of the convex portion. The film capacitor according to claim 1 , wherein a groove portion is provided at a tip of the convex portion, and the conductive wire is accommodated in the groove portion.

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