JP2011181734A - Film capacitor and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film capacitor and a method of manufacturing the same such that a capacitor element is easily made flat and an adverse influence of molding on the capacitor element is reduced. <P>SOLUTION: The film capacitor includes the capacitor element having a film wound around a support 1, having a flat part 2, as a winding shaft, wherein the support 1 comprises a plurality of members 4 and 5 which can be divided, and the capacitor element is formed by extracting the member 4 as a part of the support 1 after winding the film in a flat shape, and then extracting the other member 5 of the support 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a film capacitor including a capacitor element formed by winding a film into a flat shape and a method for manufacturing the same.

  Conventionally, in order to obtain a small capacitor having a large capacitance, a flat capacitor element having a higher storage efficiency than a cylindrical one has been used. As a method of obtaining a flat capacitor element, a film is wound with a cylindrical core to form a cylindrical capacitor element, and the capacitor element is formed into a flat shape by applying pressure to crush the capacitor element. Is generally (see, for example, Patent Document 1). In addition, when winding a film around a core, the frictional force between the films is increased to stabilize the shape of the film after winding (film winding body), and no gap is generated between the films due to thermal expansion or the like. Therefore, a constant tension (winding tension) is given to the film.

  According to the above method, since the cylindrical core is used, the winding tension can always be kept constant when the film is wound around the core, and the film is not easily wrinkled or displaced. There is an advantage that a stable film winding body can be obtained.

JP 2008-177338 A

  However, in the above method, since a cylindrical film wound body having a stable shape is formed into a flat shape by a winding tension, a large pressure is required.

  In addition, since there is a large difference in shape between before and after the film roll is molded, there is a risk of relative movement between the inner peripheral film and the outer peripheral film, resulting in wrinkles and misalignment of the film. was there.

  In addition, along with the molding, the portion of the film where the curvature is increased by the molding (cross-sectional end portions) is stretched. The winding tension at the center of the cross section is offset by this slack, and the resistance against thermal expansion of the capacitor element is reduced.

  Although the relative movement between the inner peripheral film and the outer peripheral film can be made smooth and the pressure required for molding can be reduced, a method of relaxing the winding tension can be considered. Since the state is not stable, wrinkles and displacement of the film are induced, and the resistance against thermal expansion and the like is remarkably reduced in the entire capacitor element, so that the demerit is larger.

  Also, if the winding core is made in a flat shape in advance, the shape difference between the film winding body before molding and after molding can be reduced and the above problems can be solved, but inward force due to film winding tension ( The winding force is concentrated in the vicinity of both ends of the cross section of the core, and the friction between the vicinity of both ends of the cross section and the film becomes large, so that it is difficult to remove the core from the film winding body. Further, if the extraction is forced in this state, the film on the inner peripheral side is dragged by the winding core, and there is a possibility that the function of the capacitor may be affected, such as wrinkles and displacement, or the shape of the capacitor element collapses.

  Accordingly, the present invention provides a film capacitor that eliminates the above-described drawbacks, can easily make the capacitor element flat, and can reduce adverse effects on the capacitor element due to molding, and a method for manufacturing the same. .

  In order to solve the above problems, the film capacitor of the present invention is a film capacitor including a capacitor element in which a film is wound around a support 1 having a flat portion 2 as a winding axis, and the support 1 can be divided. After comprising a plurality of members 4 and 5 and winding the film in a flat shape, a part of the member 4 of the support 1 is extracted, and then the other member 5 of the support 1 is extracted and a capacitor element is extracted. It is characterized by being molded.

  The film capacitor manufacturing method of the present invention is a film capacitor manufacturing method including a capacitor element in which a film is wound around a support body 1 having a flat portion 2 as a winding axis, and the support body 1 is divided. A plurality of members 4 and 5 that can be formed, and after the film is wound in a flat shape, a part of the member 4 of the support 1 is extracted, and then another member 5 of the support 1 is extracted, and a capacitor element It is characterized by molding.

  Specifically, the support 1 is composed of a central member 4 and both end members 5 and 5, and after winding the film in a flat shape, the central member 4 is extracted, and then the both end members 5 and 5 are extracted. ing.

  More specifically, the support 1 is composed of a wedge-shaped central member 4 and end members 5, 5 whose joint portions are inclined with respect to the axis of the support 1.

  Or it is a manufacturing method of the film capacitor which comprises the capacitor | condenser element which wound the film about the support body 1 which has the flat end part 2 as a winding axis | shaft, Comprising: The said support body 1 can be divided | segmented, and mutual junction part is said After comprising the one member 7 and the other member 8 inclined with respect to the axis of the support body 1 and winding the film in a flat shape, the one member 7 of the support body 1 is extracted, and then the support body 1 is removed. The other member 8 is extracted in the width direction to form a capacitor element.

  According to the film capacitor of the present invention, since the support body having a flat portion, that is, the support body having a flat cross section is used as the winding shaft (core), the film winding body has a flat shape, and the pressure required at the time of molding As compared with the case where a cylindrical core is used, the difference in shape between the film winding body before molding and after molding is small, so that the occurrence of wrinkles and displacement of the film can be suppressed. .

  In addition, since the elongation and sag generated during the molding of the film winding body are reduced, the film winding tension can be maintained substantially even after molding, and a flat capacitor element is manufactured while suppressing a decrease in resistance to thermal expansion and the like. Can do.

  Furthermore, since the support body is composed of a plurality of members that can be divided, the support body can be pulled out from the film winding body while separating the support body, and compared with the case where the support body is pulled out from the film winding body at a time. Since the force required to pull out the body can be reduced and the force applied to the film winding body is also reduced, it is possible to suppress wrinkling and displacement of the film at the time of extraction, and collapse of the shape of the capacitor element. Capacitor elements having a large flatness (ratio of thickness to length) can be produced without adversely affecting various functions required for the above.

  Furthermore, by constituting the support body from the central member and both end members, the tightening force is concentrated, and not the both end members of the support body where the friction with the film is large, but the tightening force is relatively small ( It can be extracted from the central member (with relatively little friction with the film), and the support can be easily extracted.

  Furthermore, by making the central member wedge-shaped, the central member is pushed out from both end members in the wide direction by the winding tension applied to the film, so that the support can be removed more easily. .

  In addition, since the support is composed of one member whose joints are inclined with respect to the axis and the other member, when the one member is slid along the other member, Since the width is narrowed and a gap is formed between the inner periphery of the film winding body, the support can be removed easily and easily compared to the one having a joint parallel to the shaft center. it can. In particular, if the size of one member (the contact area with the film) is made smaller than that of the other member, the support can be removed more easily.

It is a support body and a film, Comprising: (a) is a schematic cross section which shows the state which wound the film around the support body and formed the film winding body, (b) is the film winding of the one part member of a support body (C) is a schematic cross-sectional view showing extraction from the film winding body of other members of the support, and (d) is a film winding body after molding. It is a schematic cross section. It is 1st Example of a support body, Comprising: (a) is the side view and top view of a support body which were divided | segmented, (b) is a top view which shows the state which wound the film around the support body (C) is a top view which shows extraction from the film winding body of the one part member of a support body. It is 2nd Example of a support body, Comprising: (a) is the side view and top view of the support body which were divided | segmented, (b) is a top view which shows the state which wound the film around the support body (C) is a top view which shows extraction from the film winding body of the one part member of a support body. It is a 3rd Example of a support body, Comprising: (a) is a side view and a top view of the divided support body, (b) is a top view which shows the state which wound the film around the support body. (C) is a top view which shows extraction from the film winding body of the one part member of a support body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of the film and the support 1 cut along a plane perpendicular to the axis, and shows an outline of the present invention. The support 1 is a winding shaft (core) for winding up the film, and a plurality of members, specifically, for example, on the front and back surfaces as shown in FIGS. It is composed of a central member 4 having a substantially rectangular cross section having flat portions 2 and 2 and both end members 5 and 5 having a substantially semicircular cross section having a rounded portion 3 at one end portion. The cross-section is flattened by joining to 5 in a splittable manner.

  The film is formed by evaporating a metal such as aluminum serving as an electrode on a plastic film serving as a dielectric. For example, the film is wound around the support 1 in a state where two films are overlapped. A body 6 is formed. In addition to forming the film by vapor-depositing a metal as described above, the film may be formed by attaching an aluminum foil or the like to a plastic film, and is not limited thereto. Any structure in which a flexible electrode is provided on a flexible dielectric may be used.

  In manufacturing the film capacitor, first, the support 1 is attached to various known winding devices (not shown), and the support 1 is rotated around the axis, as shown in FIG. A film is wound around the outer periphery of the support 1. At this time, the film is wound around the support 1 in a state where a predetermined tension (winding tension) is applied. And after winding a fixed amount of film around the support body 1 and forming the flat film winding body 6, as shown in FIG.1 (b), some members (for example, center member 4) of the support body 1 are used. Are extracted in the axial direction. At this time, the tightening force is concentrated and the end members 3 and 5 having the rounded portions 3 and 3 where the friction with the film is large, but the winding force is relatively small (the friction with the film is relatively small). ) It is preferable to extract from the central member 4 having the flat portions 2 and 2. And after extracting some members of the support body 1, the remaining other members are extracted. Thereafter, in order to further flatten the film winding body 6 wound in a flat shape, pressure is applied so as to sandwich the flat surface of the film winding body 6 from both sides, thereby forming the film winding body 6 having a large flatness. . After that, if necessary, a capacitor element is formed by spraying metal on both ends of the film winding body 6 in the axial direction, and a lead wire is connected to the electrode portion in a state where one or a plurality of the capacitor elements are collected. The production of the film capacitor is completed by connecting external connection parts such as the above and resin molding.

  Thus, since the support body 1 having the flat portions 2 and 2, that is, the support body 1 having a flat cross section is used as the winding core, the film winding body 6 is flat, and the pressure required at the time of molding is reduced. As compared with the case where a cylindrical winding core is used, the difference in shape between the film winding body 6 before and after molding becomes small, and the occurrence of wrinkles and displacement of the film can be suppressed.

  In addition, since the elongation at the ends of the cross section of the film (the part where the curvature increases) and the slackness at the center of the cross section (the part where the curvature becomes small) are reduced due to molding, the winding tension is almost maintained after molding Thus, a flat capacitor element can be manufactured while suppressing a decrease in resistance against thermal expansion.

  Furthermore, since the support 1 is composed of a plurality of members 4, 5, and 5 that can be divided, the members 4, 5, and 5 of the support 1 can be extracted from the film winding body 6 at different timings. As compared with the case where the support 1 is pulled out from the film winding body 6 at a time, the force required to pull out the support 1 can be reduced and the force applied to the film winding body 6 is also reduced. Capacitor elements with large flatness can be manufactured without adversely affecting various functions required of the capacitors, because wrinkles and displacement of the film and deformation of the shape of the capacitor elements can be suppressed.

  Next, the specific shape and configuration of the support 1 will be described in detail. The support 1 of the first embodiment shown in FIG. 2 (a) is composed of a central member 4 having flat portions 2 and 2 on the front and back surfaces, and both end members 5 and 5 having rounded portions 3 at one end. It is formed in a cross-sectional flat shape by joining the central member 4 and both end members 5 and 5. Specifically, a thin-walled portion having a substantially half thickness is formed at the joint portion side end portion of the central member 4, and the joint portion side end portions of the both end members 5 and 5 are also substantially half as well. The thin portion of the central member 4 and the thin portions of both end members 5 and 5 are overlapped, and the thin portion of the central member 4 and both end members 5 and 5 is straddled. The support body 1 having a flat cross section is configured by screwing screws.

  Therefore, as shown in FIG. 2 (b), after winding the film on the support 1 so as to avoid the screws, the screws connecting the central member 4 and the end members 5, 5 of the support 1 are connected. 2, only the central member 4 can be first pulled out from the film winding body 6, and then both end members 5, 5 can be pulled out from the film winding body 6, respectively.

  Next, different embodiments of the support 1 will be described in detail. The support 1 of the second embodiment shown in FIG. 3A has a central member 4 having a smooth surface on the front and back surfaces, and both end members having a smooth surface on the front and back surfaces and a rounded portion 3 at one end. 5 and 5, and by joining the central member 4 and both end members 5 and 5, it is formed into a flat cross-sectional shape having flat portions 2 and 2 on the front and back surfaces. Unlike the first embodiment, the joint between the central member 4 and the two end members 5 and 5 is not parallel to the shaft center but has an angle with respect to the shaft center. Specifically, the central member 4 is formed in a wedge shape in plan view, and both end members 5 and 5 are formed with an inclination so as to receive the central member 4 formed in a wedge shape. Moreover, the recessed part is formed in the junction part side edge part of the center member 4, respectively, and the convex part is formed in the junction part side edge part (other end part) of the both end members 5 and 5, 5 is fitted into the concave portion of the central member 4, and a screw 1 is screwed from the wide side of the central member 4 toward both end members 5 and 5, thereby forming the support body 1 having a flat cross section. ing.

  Therefore, as shown in FIG. 3 (b), after winding the film on the support 1, the screw for joining the central member 4 and both end members 5, 5 is removed, as shown in FIG. 3 (c). In addition, the wedge-shaped center member 4 is pulled out from the both end members 5 and 5 in the wide direction by the winding tension applied to the film. For this reason, it is possible to easily extract the support 1 as compared with the first embodiment having a joint portion parallel to the axis.

  Next, further different embodiments of the support 1 will be described in detail. The support 1 of the third embodiment shown in FIG. 4A has a smooth surface on the front and back surfaces, one member 7 having a rounded portion 3 on one end, and a smooth surface on the front and back surfaces. A cross-section having flat portions 2 and 2 on the front and back surfaces by joining the one member 7 and the other member 8 to each other. It is formed in a flat shape. In addition, a thin-walled portion having a substantially half-thickness is formed at the joining portion side end portion (the other end portion) of the one member 7 and the other member 8. The support 1 is configured by overlapping the thin portions and screwing screws so as to straddle both thin portions. Further, the joint portion is not parallel to the shaft center but has an angle with respect to the shaft center.

  Therefore, as shown in FIG. 4 (b), when the film is wound on the support 1 and then the screw is removed, as shown in FIG. The member 7 is extracted so as to be pushed in the wide direction. Further, when the one member 7 is slid along the other member 8, the width of the support body 1 is narrowed, and a gap is formed between the inner peripheral surface of the film winding body 6. Compared to those having the above, the work of removing the support 1 can be performed easily and easily. Further, as shown in FIG. 4A, the size of the one member 7 (the contact area with the film) is made smaller than that of the other member 8, so that the support 1 can be easily removed.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in each of the above embodiments, the support 1 is joined by screwing a screw, but the joining method can maintain the shape of the support 1 during winding, and the support 1 is divided. If it is easy, it is not limited to screwing with screws, and various joining methods may be used. Further, the support 1 may be used as a part of the winding device, that is, as a spindle, in addition to being used as a bobbin that is detachably attached to the winding device as in the above embodiments. Even in this case, the same effects as those obtained in the above embodiments can be obtained. Further, the number of divisions of the support 1 is not limited to two or three, and may be four or more.

  1 .. Supporting body 2.. Flat part 4.. Center member 5.. Both end member 7.

Claims (5)

  A film capacitor comprising a capacitor element in which a film is wound with a support (1) having a flat portion (2) as a winding axis, and a plurality of members (4) (5) capable of dividing the support (1) ), And after the film is wound in a flat shape, a part of the support (1) (4) is extracted, and then the other member (5) of the support (1) is extracted, A film capacitor formed by molding a capacitor element.   A method of manufacturing a film capacitor comprising a capacitor element in which a film is wound with a support (1) having a flat end (2) as a winding axis, and a plurality of members (4) capable of dividing the support (1) ) (5), and after winding the film into a flat shape, some members (4) of the support (1) are extracted, and then the other members (5) of the support (1) A film capacitor manufacturing method, characterized in that a capacitor element is formed by extracting a capacitor element.   The support (1) is composed of a central member (4) and both end members (5) and (5). After the film is wound in a flat shape, the central member (4) is extracted, and then both end members ( 5) The method for producing a film capacitor according to claim 2, wherein (5) is extracted.   The said support body (1) is comprised from the wedge-shaped center member (4) and the both end members (5) (5) which made the mutual junction part inclined with respect to the axial center of the said support body (1). The manufacturing method of the film capacitor of Claim 3.   A method for producing a film capacitor comprising a capacitor element in which a film is wound with a support (1) having a flat end (2) as a winding axis, wherein the support (1) can be divided, and The joint is composed of one member (7) and the other member (8) inclined with respect to the axis of the support (1), and after the film is wound in a flat shape, the support (1) A method for producing a film capacitor, wherein the member (7) is extracted in the width direction, and then the other member (8) of the support (1) is extracted to form a capacitor element.