JP2019036656A - Caseless film capacitor and manufacturing method thereof - Google Patents

Abstract

To provide a caseless film capacitor in which a void is prevented from being obvious and of which the appearance is made satisfactory, by excellently preventing the generation of the void which influences a humidity resistance performance, volumetric efficiency and production efficiency regarding the caseless film capacitor.SOLUTION: A cavity 30 consists of a lower die nest 12 and an upper die nest 22. The upper die nest is a combination type of an annular peripheral wall part 23 which is opened in a vertical direction, and a top plate part 24 which is placed at an upper edge of the peripheral wall part. In a state where a film capacitor element 41 is accommodated in the cavity, a resin 50 is injected to fill the inside of the cavity while exhausting air by sucking a negative pressure in the cavity via a mating surface A between the peripheral wall part and the top plate part. As the upper die nest, an entire surface of a bottom face 24a of a front plate part opposite to the cavity is formed into a flat surface, and the flat bottom face 24a and an inner peripheral surface 23b of the peripheral wall part cross each other in a substantial corner orthogonal state.SELECTED DRAWING: Figure 1

Description

  The present invention provides a film capacitor element in which a pair of electrode lead metal electrodes (metallicons) are formed on both end faces, and an external lead terminal (bus bar) that is electrically connected to and drawn from each of the pair of metal electrodes. Further, the present invention relates to a caseless film capacitor having an exterior resin that covers a part of the external lead terminal excluding the external connection terminal portion on the free end side of the external lead terminal and the entire film capacitor element. Further, a mold in which a cavity is constituted by a lower mold insert incorporated in a lower mold and an upper mold insert incorporated in an upper mold is used, and the inside of the cavity is accommodated in a state where a film capacitor element is housed in the cavity. The present invention relates to a method of manufacturing a caseless film capacitor in which an exterior resin is injected and filled into a cavity while sucking and exhausting with a negative pressure.

  Conventionally, in order to reduce the size and weight of film capacitors, the resin is injected into the upper and lower molds without using a resin case, and the film capacitor element is covered with an exterior resin (exterior body). A filmless capacitor is known (see, for example, Patent Document 1).

  FIGS. 11A and 11B show a caseless film capacitor X ′ in the prior art. This caseless film capacitor X 'is electrically connected to a film capacitor element 41 having a pair of positive and negative electrode lead metal electrodes 41a and 41a formed on both end faces, and a pair of metal electrodes 41a and 41a, respectively. A part of the external lead terminals excluding the external connection terminals 42a and 42a on the free end side of the external lead terminals 42 and 42 and the external connection terminals 42a and 42a on the external lead terminals 42 and 42 and the entire film capacitor element 41. It has. In this conventional caseless film capacitor X ′, each of an upper surface 43a of a plurality of surfaces forming the outer surface of the exterior resin 43 and side surfaces 43b forming a peripheral surface in a state adjacent to the upper surface 43a. Is formed at a corner KA in a curved surface state. The main part of the upper surface 43a and the main part of the side surface 43b are both flat surfaces except for the boundary portion exhibiting the corner radius KA between the upper surface 43a and the side surface 43b. Note that they are substantially orthogonal to each other on the extended surface.

  In the caseless film capacitor X ′ having such a shape, a void 51 may occur in the vicinity of the corner radius KA on the upper surface 43 a of the exterior resin 43. In parallel with the filling and filling of the resin for exterior packaging into the mold cavity, the air in the cavity is exhausted by negative pressure suction. If this exhaust is insufficient, the void 51 remains on the exterior resin 43. As a result, the appearance of the caseless film capacitor X ′ is impaired.

  Hereinafter, this point will be described in relation to the manufacturing method of the caseless film capacitor X ′ in the prior art.

  12 is a cross-sectional view showing the structure of the main part of a manufacturing apparatus for carrying out the method of manufacturing a caseless film capacitor in the conventional example, FIG. 13 is a cross-sectional view of the main part of the upper mold, and FIG. 14 is an exploded view of the upper mold insert. It is the perspective view (a) of a state, and sectional drawing (b), (c). Among these, (b) is sectional drawing in the II line in (a), (c) is sectional drawing in the II-II line in (a).

  In these drawings, 10 is a lower mold in the mold 1, 20 is an upper mold in the mold 1, 11 is a lower mold pocket (recess) formed in the lower mold 10, and 21 is an upper mold formed in the upper mold 20. A mold pocket, 12 is a lower mold nest incorporated in the lower mold pocket 11 in a housed state, 13 is an auxiliary nest built in the same lower mold pocket 11 in a housed state, and 22 is an upper mold nest housed in the upper mold pocket 21. It is. The lower mold insert 12 is a box-shaped integrated body composed of a bottom portion 12a and a peripheral wall portion 12b, and constitutes a lower cavity 30a. The auxiliary nest 13 mounts and supports the external connection terminal portions 42a and 42a in a horizontal posture on the free end side of the pair of positive and negative external lead terminals 42 and 42. An air vent 14 is formed on the upper surface of the lower mold 10 so as to be adjacent to the upper surface of the auxiliary insert 13. The upper mold 20 is formed with an air vent 25 that communicates the air vent 14 of the lower mold 10 and the external space of the mold 1 (upper mold 20) through an L-shaped path.

  The upper mold insert 22 is divided into a peripheral wall portion 23 and a top plate portion 24 with respect to the lower mold insert 12 of the box-type integral, and the top plate portion 24 is placed on the upper edge 23a of the peripheral wall portion 23. The combination type is configured to close the upper opening of the peripheral wall portion 23. The upper mold insert 22 (the peripheral wall portion 23 and the top plate portion 24) of this combination type is incorporated in the upper mold pocket 21 so as to be accommodated, and the upper cavity 30b of the upper mold insert 22 and the lower cavity 30a of the lower mold insert 12 The cavity 30 of the mold 1 is constituted by the above.

In the upper mold insert 22, a recessed portion 24b is formed in the top plate portion 24 so as to be recessed upward to form the upper end portion of the upper cavity 30b (see FIG. 13). Peripheral portion of the recessed portion 24b is formed on the corner radius portions 24b ₁ of the curved state. A mating surface A between the peripheral wall portion 23 and the top plate portion 24 extends outward in the horizontal direction from the lowermost end 24b ₂ of the corner radius portion 24b ₁ .

  In the cavity 30 of the mold 1, the film capacitor element 41 from which the external lead terminals 42 and 42 are drawn out is accommodated. The external connection terminal portions 42 a and 42 a on the free end side of the external lead terminals 42 and 42 are sandwiched between the mating surfaces B of the lower mold insert 12 and the upper mold insert 22. The outermost end portion of the external connection terminal portion is positioned with being sandwiched between the upper surface of the auxiliary insert 13 and the lower surface of the upper mold 20.

  Resin is injected and filled into the cavity 30 while the air in the cavity 30 of the mold 1 is exhausted to the outside through the air vents 25 and 14 by negative pressure suction. Air in the cavity 30 flows from the mating surface A of the peripheral wall portion 23 and the top plate portion 24 to the outer peripheral surface 23c of the peripheral wall portion 23, the mating surface C of the auxiliary insert 13 and the upper die 20, and the air vent on the upper surface of the lower die 10. 14. It is exhausted to the outside through the air vent 25 of the upper mold 20. Until the resin reaches the height position of the mating surface A between the peripheral wall portion 23 and the top plate portion 24, the air in the cavity 30 is well discharged by negative pressure suction.

In the final stage of the resin filling the resin flows into the recess 24b of the lower surface of the top plate 24, also flows into the corner rounded portion 24b ₁ of the curved state of the peripheral portion of the recessed portion 24b. The resin that has flowed into the corner radius portion 24b ₁ becomes a boundary portion of the curved surface state that forms the corner radius KA between the upper surface 43a and the side surface 43b in the exterior resin 43 after solidification.

JP 2009-49149 A

  However, in the final process of resin filling, the resin also enters the recessed portion 24 b on the lower surface of the top plate portion 24. At this time, the resin exceeds the height position of the mating surface A between the peripheral wall portion 23 and the top plate portion 24. As a result, the injected and filled resin blocks the exhaust path (mating surface A), so that resistance to the exhaust of the air in the cavity 30 to the outside is applied, and the exhaust from the cavity 30 becomes insufficient. . In the exterior resin 43 obtained as a result of the resin injection and filling being solidified, the air in the cavity 30 is not discharged to the outside and the void 51 may remain at the boundary portion of the curved surface forming the corner radius KA. (See FIG. 11).

  The void 51 not only detracts from the appearance of the caseless film capacitor X ′. The presence of the void 51 results in a decrease in the thickness of the exterior resin 43 in that region, leading to deterioration of the moisture resistance of the caseless film capacitor X ′, which is a function of the exterior resin 43. Regardless of the voids, it is sufficient to increase the thickness of the exterior resin in order to ensure the required moisture resistance performance. However, if this is done, the volumetric efficiency will decrease, leading to an increase in the amount of resin, and thus a decrease in production efficiency. If the size and number of the voids 51 are about the same as those shown in FIG. 11A, the product value is not greatly deteriorated, but if the voids 51 become larger or larger as shown in FIG. It loses value and goes to disposal, resulting in a significant drop in productivity.

  The present invention was created in view of such circumstances, and provides a method for producing a caseless film capacitor that can favorably prevent the occurrence of voids that affect moisture resistance, volumetric efficiency, and production efficiency. In addition, an object of the present invention is to provide a caseless film capacitor having a good appearance in which voids do not appear.

  The present invention solves the above problems by taking the following measures.

  The first caseless film capacitor manufacturing method according to the present invention uses a mold in which a cavity is formed by a lower mold insert incorporated in a lower mold and an upper mold insert incorporated in an upper mold. The insert is configured in a combination type having an annular peripheral wall portion opened in the vertical direction and a top plate portion placed on the upper end edge of the peripheral wall portion so as to close the upper opening, and the film capacitor element is connected to the cavity. A caseless film capacitor in which a resin is injected and filled into the cavity while suctioning and exhausting the inside of the cavity through the mating surface of the peripheral wall portion and the top plate portion while being housed In the manufacturing method of the above, as the upper mold insert, the entire lower surface of the top plate portion facing the cavity is formed into a flat surface, and the flat lower surface and the peripheral wall And performing injection molding using those and the inner circumferential surface of the cross in the state of the corner substantially orthogonal.

  The intersecting state formed by the flat bottom surface of the top plate portion and the inner peripheral surface of the peripheral wall portion at the corner angle of the butting may be an orthogonal state in the sense of exactly 90 °, but is orthogonal from the viewpoint of mold releasability. It is considered preferable to be in a state inclined by several degrees from the state (so-called mold draft), and in this sense, it is expressed as “crossing in a state where the corners are substantially orthogonal” in this specification.

  In the final process of injecting and filling the resin into the mold cavity, the injected and filled resin reaches the uppermost position of the cavity. The uppermost position of the cavity coincides with the flat lower surface of the top plate portion of the upper mold insert, and the flat lower surface of the top plate portion of the upper mold insert facing the cavity is substantially perpendicular to the inner peripheral surface of the peripheral wall portion. Cross at. And this flat lower surface exists in the same height position also with the mating surface of a surrounding wall part and a top-plate part. Therefore, the external discharge of the air in the cavity is continued through the mating surface of the peripheral wall portion and the top plate portion until the resin is filled at the highest position of the cavity, that is, at the same height as the flat lower surface of the top plate portion. Will be. That is, the air in the cavity is discharged smoothly until the final filling stage of the resin, and in the exterior resin of the caseless film capacitor as a molded product, voids remain on any outer surface including the vicinity of the corner of the upper surface. Absent.

  The second caseless film capacitor manufacturing method according to the present invention uses a mold in which a cavity is constituted by a lower mold nest incorporated in a lower mold and an upper mold nest incorporated in an upper mold. The upper mold insert has an annular peripheral wall portion opened in the vertical direction, and the cavity is inserted through the mating surface of the upper surface of the peripheral wall portion and the inner bottom surface of the upper mold with the film capacitor element housed in the cavity. In the method of manufacturing a caseless film capacitor in which resin is injected and filled into the cavity while suctioning and evacuating the inside, the inner bottom surface of the upper mold and the upper surface of the peripheral wall portion are formed flat. The injection molding is carried out using a material in which the inner bottom surface of the upper mold and the inner peripheral surface of the peripheral wall portion intersect in a substantially orthogonal state.

  In the first manufacturing method described above, the upper mold insert is composed of an annular peripheral wall portion and a top plate portion placed on the upper end edge thereof, whereas in the second manufacturing method, the upper mold insert is opened in the vertical direction. An upper mold insert having an annular peripheral wall portion but having no top plate portion is used. The upper mold insert which is such a peripheral wall is incorporated in the upper mold. Accordingly, the uppermost position of the mold cavity coincides with the inner bottom surface of the upper mold and the upper surface of the peripheral wall portion. That is, the inner bottom surface of the upper mold facing the cavity intersects with the inner peripheral surface of the peripheral wall portion in a state of being substantially orthogonal to the corner. The inner bottom surface of this upper mold is a mating surface with the upper surface of the peripheral wall portion.

  In the final process of injecting and filling the resin into the mold cavity, the injected and filled resin reaches the uppermost position of the cavity. Then, the air inside the cavity is discharged outside through the mating surface of the upper surface of the peripheral wall and the inner bottom surface of the upper mold until the resin is filled at the highest position of the cavity, that is, at the same height as the inner bottom surface of the upper mold. Will be continued. That is, the air in the cavity is discharged smoothly until the final filling stage of the resin, and in the exterior resin of the caseless film capacitor as a molded product, voids remain on any outer surface including the vicinity of the corner of the upper surface. Absent.

  On the other hand, a first caseless film capacitor according to the present invention is a film capacitor element in which a pair of electrode lead metal electrodes are formed on both end faces, and is electrically connected to each of the pair of metal electrodes. A caseless film capacitor having an exterior resin that externally covers a part of the external lead terminal excluding the external lead terminal and the external connection terminal portion on the free end side of the external lead terminal and the whole film capacitor element, The upper surface of the plurality of surfaces forming the outer surface of the exterior resin intersects with a state in which each of the plurality of side surfaces forming the peripheral surface adjacent to the upper surface is continuously refracted at a substantially right angle. In addition, a boundary portion between the upper surface and the plurality of side surfaces is formed in a non-curved ridgeline shape.

  The caseless film capacitor obtained by injection molding according to the first or second caseless film capacitor manufacturing method of the present invention also corresponds to the first caseless film capacitor of the present invention described above. In the caseless film capacitor, the upper surface of the plurality of surfaces forming the outer surface of the exterior resin and each of the plurality of side surfaces forming the peripheral surface in a state adjacent to the upper surface are substantially continuous. It intersects in a state of being refracted at a right angle, and has a feature that the boundary portion between the upper surface and the plurality of side surfaces is formed in a non-curved ridgeline shape.

  In addition, as the second caseless film capacitor obtained by injection molding by the first or second caseless film capacitor manufacturing method, on the peripheral surface adjacent to the upper surface of the outer surface of the exterior resin, A parting line is also included that has the feature that the parting line is formed in two locations in the vertical direction, the external lead terminal position and the upper end position.

  In these first or second caseless film capacitors, no voids remain on any outer surface including the vicinity of the corner of the upper surface of the exterior resin. Since it is possible to form a caseless film capacitor without causing voids in the exterior resin, it is possible to prevent a decrease in moisture resistance due to voids. There is no need to increase the thickness of the extra exterior resin as in the prior art, and the amount of resin does not increase. Therefore, volumetric efficiency and production efficiency are improved. The appearance of the caseless film capacitor is also high quality.

  According to the present invention, since a caseless film capacitor can be molded without causing voids in the exterior resin, the improvement in volumetric efficiency and production efficiency can be achieved while preventing a decrease in moisture resistance, and high appearance with no voids. A quality caseless film capacitor can be provided.

Sectional drawing which shows the structure of the principal part of the manufacturing apparatus for enforcing the manufacturing method of the caseless film capacitor in the Example of this invention The perspective view of the partially transparent state of the structure of the principal part of the manufacturing apparatus in the Example of this invention The perspective view of the lower mold | type of the manufacturing apparatus in the Example of this invention The perspective view which shows the state which set the film capacitor element to the lower mold | type of the manufacturing apparatus in the Example of this invention. Sectional drawing of the principal part of the upper mold | type of the manufacturing apparatus in the Example of this invention The perspective view (a) and sectional drawing (b), (c) of the decomposition | disassembly state of the upper mold insert of the manufacturing apparatus in the Example of this invention Explanatory drawing of the mode of the exhaust_gas | exhaustion from the mating surface of a surrounding wall part and a top-plate part in the Example of this invention. The perspective view which shows the external appearance of the caseless film capacitor obtained by the injection molding in the Example of this invention Sectional drawing which shows the structure of the principal part of the manufacturing apparatus for enforcing the manufacturing method of the caseless film capacitor in another Example of this invention The perspective view (a) which shows the external appearance of the caseless film capacitor in another Example of this invention, and the perspective view (b) which shows the state which removed the cooling plate The perspective view which shows the external appearance of the caseless film capacitor in a prior art example Sectional drawing which shows the structure of the principal part of the manufacturing apparatus for enforcing the manufacturing method of the caseless film capacitor in a prior art example Sectional drawing of the principal part of the upper mold | type of the manufacturing apparatus in a prior art example The perspective view (a) and sectional drawing (b), (c) of the decomposition | disassembly state of the upper mold insert of the manufacturing apparatus in a prior art example

  Hereinafter, the embodiment of the caseless film capacitor manufacturing method and caseless film capacitor of the present invention having the above-described configuration will be described in detail at the level of specific examples.

  1 is a cross-sectional view showing the structure of a main part of a manufacturing apparatus for carrying out a method of manufacturing a caseless film capacitor in an embodiment of the present invention, FIG. 2 is a perspective view of a partially transparent state thereof, and FIG. 4 is a perspective view showing a state in which the film capacitor element 41 is set on the lower mold 10, FIG. 5 is a cross-sectional view of the main part of the upper mold 20, and FIG. 6 is a perspective view of the disassembled state of the upper mold insert 22. It is figure (a) and sectional drawing (b), (c). Among these, (b) is sectional drawing in the II line in (a), (c) is sectional drawing in the II-II line in (a). FIG. 7 is an explanatory view of the state of exhaust from the mating surface A of the peripheral wall portion 23 and the top plate portion 24, and FIG. 8 is a perspective view showing the appearance of the caseless film capacitor X obtained by injection molding.

  In these drawings, 1 is a mold, 10 is a lower mold in the mold 1, 20 is an upper mold in the mold 1, 11 is a lower mold pocket formed in the lower mold 10, and 21 is formed in the upper mold 20. Upper mold pocket 12, 12 is a lower mold nest incorporated in a lower mold pocket 11 formed in the lower mold 10, 13 is an auxiliary nest incorporated in the same lower mold pocket 11 in an accommodated state, and 14 is a lower mold 10 , 22 is an upper mold nest accommodated in the upper mold pocket 21, 23 is a peripheral wall portion constituting the upper mold nest 22, 23a is an upper edge thereof, 23b is an inner peripheral surface thereof, and 23c is an outer periphery thereof. Similarly, the surface 24 is the top plate portion constituting the upper mold insert 22, 24 a is the flat bottom surface, 25 is the air vent formed in the upper mold 20, 30 is the cavity of the mold 1, 30 a is the lower cavity, 30 b is the upper part Is a cavity

  X is a caseless film capacitor, 41 is a film capacitor element, 41a is a metal electrode, 42 is an external lead terminal, 42a is an external connection terminal, 43 is an exterior resin (after solidification), 43a is an upper surface of the exterior resin 43, 43b is a side surface of the exterior resin 43, and 50 is an exterior resin. As the exterior resin 50, both a thermosetting resin and a thermoplastic resin can be used, but a thermosetting resin such as an epoxy resin is preferably used.

  As shown in FIG. 1 and FIG. 2, a lower mold insert 12 and an auxiliary insert 13 are accommodated in a side butted state in a lower mold pocket 11 formed in the lower mold 10. The lower mold insert 12 is a box-shaped integrated body composed of a bottom portion 12a and a peripheral wall portion 12b, and constitutes a lower cavity 30a. The lower half of the film capacitor element 41 is accommodated in the lower cavity 30a (see FIGS. 1 and 4). The external connection terminal portions 42a and 42a, which are horizontal plates at the free ends of the external lead terminals 42 and 42 drawn from the pair of positive and negative metal electrodes 41a and 41a at both ends in the axial direction of the film capacitor element 41, are flush with each other. In an attitude, it extends from the upper surface 12 c of the lower mold insert 12 to the upper surface of the auxiliary insert 13. Shallow concave portions into which the external connection terminal portions 42a and 42a are fitted are formed on the upper surface 12c of the lower mold insert 12 and the upper surface of the auxiliary insert 13 (see FIGS. 3 and 4). An air vent 14 is formed on the upper surface of the lower mold 10 adjacent to the lower mold pocket 11. The upper mold 20 is formed with an air vent 25 that connects the air vent 14 and the outer space of the mold 1 (upper mold 20) through an L-shaped path.

  An upper mold insert 22 comprising a peripheral wall portion 23 and a top plate portion 24 is accommodated in an upper mold pocket 21 formed in the upper mold 20 (see FIGS. 1, 5, and 6). The peripheral wall portion 23 is formed in a hollow ring shape that opens in the vertical direction. With respect to the upper mold pocket 21, the top plate portion 24 is set first, and then the peripheral wall portion 23 is set. As a result, the top plate portion 24 is placed on the upper end edge 23a of the peripheral wall portion 23 and closes the upper opening of the hollow annular peripheral wall portion 23. An upper cavity 30b is formed in the upper mold insert 22 constituted by a combination of the peripheral wall portion 23 and the top plate portion 24, and the upper half of the film capacitor element 41 is accommodated in the upper cavity 30b. The lower cavity 30a of the lower mold insert 12 and the upper cavity 30b of the upper mold insert 22 constitute the cavity 30 of the mold 1, and the resin 50 is injected and filled into the cavity 30 (see FIG. 7). Note that illustration of the injection filling path (spool runner) of the resin 50 is omitted.

  As for the top plate portion 24 in the upper mold insert 22, the entire lower surface 24a of the top plate portion 24 facing the cavity 30 (upper cavity 30b) is formed as a flat surface, and the flat lower surface 24a and the inner peripheral surface 23b of the peripheral wall portion 23. Are crossed in a state where the corners are substantially orthogonal (see FIGS. 1 and 5 to 7). That is, the inner peripheral surface 23b of the peripheral wall portion 23 is in a substantially vertical posture from the lower end to the upper end, the entire upper end edge 23a of the peripheral wall portion 23 is in a horizontal posture, and the flat lower surface 24a of the top plate portion 24 is horizontal over the entire surface. It is a posture. Therefore, the inner peripheral surface 23b of the peripheral wall portion 23 and the flat lower surface 24a of the top plate portion 24 are in abutment in a direct contact state (see FIGS. 5 and 6). The flat lower surface 24a of the top plate portion 24 and the inner peripheral surface 23b of the peripheral wall portion 23 may be in an orthogonal state in the sense of 90 °, but are inclined several degrees from the orthogonal state from the viewpoint of mold releasability. It is preferable to be in a state. This is set as a so-called mold draft, and in this embodiment, the draft is about 2 degrees.

  The cavity 30 of the mold 1 communicates with the external space. This point will be described in more detail with reference to FIG. 5 showing a cross-sectional view of the main part of the upper mold 20. From the mating surface B of the upper surface of the lower mold insert 12 and the lower surface of the upper mold insert 22 and the mating surface A of the peripheral wall portion 23 and the top plate portion 24 of the upper mold insert 22, the mating surface of the auxiliary insert 13 and the upper mold 20 The air vent 14 on the lower mold 10 and the air vent 25 in the upper mold 20 communicate with the external space via C (see FIGS. 1 and 5). The mating surfaces A, B, and C are all fine gaps, but the air in the cavity 30 can be sufficiently exhausted by the action of negative pressure suction. The pair of positive and negative external connection terminal portions 42 a and 42 a are sandwiched between the mating surface B and the mating surface C. Arrows H1 to H8 indicate exhaust paths (see FIGS. 1, 2, and 5).

  Until the filling of the resin 50 into the cavity 30 reaches the mating surface B, the exhaust is performed mainly through a route of H1, H4, H5, H6, H7, and H8. When the filling exceeds the mating surface B, the mating surface B is blocked with the filling resin, so that the exhaust is performed mainly through the route of H2-> H3-> H4-> H5-> H6-> H7-> H8.

  As shown by the upward arrow Y in FIGS. 7A and 7B showing the state of exhaust from the mating surface A of the peripheral wall portion 23 and the top plate portion 24, the resin 50 is sequentially lowered in the upper cavity 30b. It rises from the side toward the upper side. The wavy lines J1 to J6 representing the surface of the resin 50 gradually increase in level, but this is matched with the passage of time. That is, J1 → J2 → J3 → J4 → J5 → J6 in this order, and in FIG. 7A, the solid line segment J4 is the current surface close to the final stage. The surface J4 is close enough to the flat lower surface 24a of the top plate portion 24. The uppermost portion of the upper cavity 30 b is an air reservoir, which communicates with the mating surface A between the peripheral wall portion 23 and the top plate portion 24. This is because the filling resin has not yet reached the height position of the mating surface A, and the mating surface A is not blocked by the filling resin.

  Filling further proceeds from the stage of FIG. 7A, and when the stage of FIG. 7B is reached, the surface J6 of the resin 50 is at a height position closest to the flat lower surface 24a of the top plate portion 24. Even at this time, the mating surface A has not been blocked by the filling resin.

  As described above, the entire amount of air in the cavity 30 is substantially completely exhausted through the route of H2, H3, H4, H5, H6, H7, and H8. As a result, the resin 50 spreads throughout the entire area of the cavity 30. That is, voids can be prevented from remaining in the exterior resin 43 of the caseless film capacitor X formed by the solidification of the resin 50.

  In FIG. 8, which is a perspective view showing the appearance of the caseless film capacitor X formed by the manufacturing method described above, a film capacitor element 41 is formed by winding a metallized film composed of a dielectric film and a metal vapor-deposited electrode. Construct a columnar metallized film wound body, press the metallized film wound body in the diametrical direction to form an oblong flat columnar body, and spray metal particles on both ends of the flat columnar body in the axial direction A pair of positive and negative metal electrodes 41a, 41a is formed. A pair of positive and negative external lead terminals 42, 42 are electrically connected to the metal electrodes 41a, 41a, and the refracted free end side horizontal portion functions as the external connection terminal portions 42a, 42a. The pair of positive and negative external connection terminal portions 42 a and 42 a are disposed at the same height position in the axial direction of the film capacitor element 41. This is because the lower mold insert 12 and the upper mold insert 22 are clamped by the parting surfaces. A part of the external lead terminals 42 and 42 excluding the external connection terminal portions 42 a and 42 a and the entire film capacitor element 41 are covered and protected by the exterior resin 43.

  Further, as an appearance feature of the caseless film capacitor X formed by the manufacturing method described above, a parting line is formed on the side surface 43b (a peripheral surface adjacent to the upper surface 43a) of the outer surface of the exterior resin 43. It is formed in two places, the external lead terminal position and the upper end position in the vertical direction. Specifically, the parting line PL1 is formed at the position of the external lead terminal portions 42a and 42a in the vertical direction, and the parting line PL2 is formed at the position near the upper surface 43a in the vertical direction.

  In the caseless film capacitor X configured as described above, an upper surface 43a among a plurality of surfaces that form the outer surface of the exterior resin 43, and a side surface that forms a peripheral surface adjacent to the upper surface 43a. Each of 43b cross | intersects the state which refracts | biases substantially at right angle continuously, and the boundary part of the upper surface 43a and the side surface 43b is formed in the ridgeline shape of a non-curved surface.

  In the caseless film capacitor X obtained by injection molding, generation of voids is prevented on any outer surface including the vicinity of the corner of the upper surface 43a of the exterior resin 43 (see FIG. 8). That is, there is no decrease in moisture resistance performance due to voids, no extra thickness increase in the exterior resin 43, and no increase in the amount of resin, and volume efficiency and production efficiency are high. Of course, the appearance quality is also high.

  In the above embodiment, one exhaust path is formed by the air vent 14 of the lower mold 10 and the L-shaped air vent 25 of the upper mold 20, but the number of such exhaust paths is limited. It is not intended to be determined arbitrarily according to conditions and circumstances. The same applies to the route for filling and filling the resin 50 (spool runner).

  FIG. 9 is a cross-sectional view showing the structure of the main part of a manufacturing apparatus for carrying out a method for manufacturing a caseless film capacitor in another embodiment. In FIG. 9, the same reference numerals as those used in FIG. 5 of the previous embodiment denote the same components, and detailed description thereof will be omitted.

  In the embodiment of FIG. 9, the upper mold insert 22 has a hollow annular peripheral wall portion 23 opened in the vertical direction, but does not have a top plate portion (24). That is, the upper mold nest 22 is composed of only the annular peripheral wall part 23 (the upper mold nest and the peripheral wall part are synonymous). The upper mold insert 22 as a single peripheral wall portion 23 is incorporated in the upper mold pocket 21 in the accommodated state.

  In the case of this embodiment, the uppermost position of the cavity 30 of the mold 1 coincides with the inner bottom surface 21a of the upper mold pocket 21 and the upper surface of the peripheral wall portion 23 (upper mold insert 22) in the upper mold 20. That is, the inner bottom surface 21a of the upper mold 20 facing the cavity 30 intersects the inner peripheral surface 23b of the peripheral wall portion 23 (upper mold insert 22) in a state where the corner is substantially orthogonal. The inner bottom surface 21a of the upper mold 20 is a mating surface A 'with the upper surface 23a of the peripheral wall portion 23 (upper mold insert 22).

  According to the manufacturing method of the present embodiment, in the final process of injecting and filling the resin into the cavity 30 of the mold 1, when the injected and filled resin reaches the uppermost position of the cavity 30, the resin becomes the uppermost position of the cavity 30. That is, the cavity through the mating surface A ′ between the upper surface 23a of the peripheral wall portion 23 (upper mold insert 22) and the inner bottom surface 21a of the upper mold 20 until the same height as the inner bottom surface 21a of the upper mold 20 is filled. External discharge of internal air continues. As a result, the air in the cavity is smoothly discharged until the final filling stage of the resin.

  Therefore, the caseless film capacitor obtained by injection molding is the same as the caseless film capacitor X obtained by injection molding by the manufacturing method of the previous embodiment shown in FIG. That is, voids are prevented from occurring on any outer surface including the vicinity of the corner of the upper surface 43a of the exterior resin 43.

As a modified example, as shown in FIGS. 10A and 10B, the cooling plate 60 may be fitted into a concave groove 43 a ₁ formed in the upper surface 43 a of the exterior resin 43. FIG. 10A is a perspective view showing the appearance of the caseless film capacitor, and FIG. 10B is a perspective view showing a state where the cooling plate 60 is removed.

  The upper surface of the cooling plate 60 is flush with the upper surface 43 a of the exterior resin 43. Two parting lines PL1 and PL2 are formed at two locations in the vertical direction on the peripheral surface adjacent to the upper surface 43a of the outer surface of the exterior resin 43. That is, the parting line PL1 is formed at the position of the external connection terminal portions 42a and 42a on the free end side of the external lead terminals 42 and 42, and the parting line PL2 is formed at the position of the cooling plate 60 near the upper end of the exterior resin 43. Has been.

  In the modification shown in FIG. 10 as well, a caseless film capacitor can be manufactured while preventing the generation of voids as in the embodiment.

  In addition, about the manufacturing method of a caseless film capacitor, you may comprise the lower mold insert 12 by the combination of the surrounding wall part and top-plate part similar to the upper mold insert 22. FIG. The caseless film capacitor obtained by the manufacturing method intersects the state in which the upper surface 43a of the exterior resin 43 and the side surface 43b that forms a peripheral surface adjacent to the upper surface 43a are continuously refracted at a substantially right angle. In addition, the boundary portion between the upper surface 43a and the side surface 43b is not only formed into a non-curved ridgeline, but also the lower surface of the exterior resin 43 and the side surface 43b that forms a peripheral surface in a state adjacent to the lower surface. Are continuously refracted at a substantially right angle, and the boundary between the lower surface and the side surface 43b is also formed in a non-curved ridgeline shape.

  In the above embodiment, the external connection terminal portions 42a and 42a of the pair of positive and negative external lead terminals 42 and 42 are drawn in the same direction from the same height position, but the height position and direction are limited to this. Rather, it can be determined arbitrarily according to conditions and circumstances.

  INDUSTRIAL APPLICABILITY The present invention is useful as a technique for obtaining a high-quality caseless film capacitor having an excellent appearance that prevents a decrease in moisture resistance and does not cause voids in an exterior resin while improving volumetric efficiency and production efficiency. .

DESCRIPTION OF SYMBOLS 1 Mold 10 Lower mold 12 Lower mold insert 20 Upper mold 21a Inner bottom surface 22 Upper mold insert 23 Peripheral wall portion 23a Upper edge of the peripheral wall portion 23b Inner peripheral surface of the peripheral wall portion 24 Top plate portion 24a Flat lower surface (lower surface of the top plate portion)
30 Cavity 41 Film Capacitor Element 41a Metal Electrode 42 External Lead Terminal 42a External Connection Terminal Part 43 Exterior Resin 43a Top Surface of Exterior Resin 43b Side Surface of Exterior Resin 50 Resin A, A 'Matching Surface X Caseless Film Capacitor

Claims (4)

A mold having a cavity formed by a lower mold insert embedded in a lower mold and an upper mold insert embedded in an upper mold is used. The upper mold insert is an annular peripheral wall portion opened in the vertical direction and its upper opening. A top plate portion placed on the upper edge of the peripheral wall portion so as to block the peripheral wall portion, and the peripheral portion of the peripheral wall portion and the top plate portion in a state where the film capacitor element is housed in the cavity. In the method of manufacturing a caseless film capacitor of the method of injecting and filling resin into the cavity while suctioning and exhausting the inside of the cavity through the mating surface of
As the upper mold nesting, a top surface of the top plate portion facing the cavity is formed as a flat surface, and the flat bottom surface and the inner peripheral surface of the peripheral wall portion intersect with each other in a substantially perpendicular state. A method of manufacturing a caseless film capacitor, wherein injection molding is performed. Using a mold in which a cavity is constituted by a lower mold nest incorporated in a lower mold and an upper mold nest incorporated in an upper mold, the upper mold nest has an annular peripheral wall portion opened in the vertical direction, In a state where the film capacitor element is housed in the cavity, the inside of the cavity is sucked and evacuated through the mating surface of the upper surface of the peripheral wall portion and the inner bottom surface of the upper mold, and the resin is discharged from the cavity. In the manufacturing method of the caseless film capacitor of the method of injecting and filling,
Injection molding using the inner bottom surface of the upper mold and the upper surface of the peripheral wall portion formed in a flat surface, and the inner bottom surface of the upper mold and the inner peripheral surface of the peripheral wall portion intersect in a substantially orthogonal state A method for producing a caseless film capacitor, comprising:   A film capacitor element having a pair of electrode lead metal electrodes formed on both end faces, an external lead terminal that is electrically connected to each of the pair of metal electrodes, and a free end side of the external lead terminal A caseless film capacitor having an exterior resin covering the part of the external lead terminal excluding the external connection terminal portion and the entire film capacitor element, and a plurality of surfaces forming an outer surface of the exterior resin. And a plurality of side surfaces forming a peripheral surface adjacent to the upper surface are continuously refracted at substantially right angles, and a boundary portion between the upper surface and the plurality of side surfaces is A caseless film capacitor characterized by being formed into a non-curved ridgeline.   A film capacitor element having a pair of electrode lead metal electrodes formed on both end faces, an external lead terminal that is electrically connected to each of the pair of metal electrodes, and a free end side of the external lead terminal A caseless film capacitor having an exterior resin that externally covers a part of the external lead terminal excluding the external connection terminal portion and the entire film capacitor element, and a peripheral surface adjacent to the upper surface of the outer surface of the exterior resin A caseless film capacitor, wherein a parting line is formed at two positions in the vertical direction, the external lead terminal position and the upper end position.

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