JP6145631B2 - Case mold type capacitor - Google Patents

Description

  The present invention relates to a case mold type capacitor that is used in various electronic devices, electrical devices, industrial devices, automobiles, and the like, and is particularly suitable for smoothing, filtering, and snubbing of a motor drive inverter circuit of a hybrid vehicle.

  In recent years, from the viewpoint of environmental protection, all electric devices are controlled by inverter circuits, and energy saving and high efficiency are being promoted. In particular, in the automobile industry, hybrid vehicles (hereinafter referred to as HEVs) that run on electric motors and engines have been introduced into the market, and the development of technologies relating to energy saving and high efficiency has been activated, which is friendly to the global environment.

  Since an electric motor for HEV has a high operating voltage range of several hundred volts, a metallized film capacitor having high withstand voltage and low loss electric characteristics has attracted attention as a capacitor used in connection with such an electric motor. In addition, the trend of adopting metalized film capacitors with a very long life is also conspicuous due to the demand for maintenance-free in the market.

  And, metallized film capacitors used for HEVs are strongly required to have external environmental performance such as moisture resistance and heat resistance for reasons such as their installation location, and therefore, generally a plurality of metallizations connected in parallel by bus bars. A film capacitor is housed in a resin case, and a mold resin is cast into the resin case. By casting the mold resin in this manner, the metalized film capacitor is protected from the intrusion of moisture from the outside and the influence of heat.

  A conventional configuration of a case mold type capacitor containing such a metallized film capacitor will be described with reference to FIGS. 7A and 7B using the case mold type capacitor described in Patent Document 1 as an example. FIG. 7A is a perspective view showing a configuration of a case mold type capacitor described in Patent Document 1. FIG. FIG. 7B is an example in which the shape of the bus bar of the case mold type capacitor described in Patent Document 1 is changed in accordance with the change in the connection status to other components outside the case mold type capacitor.

  As shown in FIG. 7A, a conventional case mold type capacitor 101 has bus bars 102 and 103 made of copper plates or the like connected to both end faces of a metallized film capacitor element (not shown), and these metallized film capacitors. The elements and the bus bars 102 and 103 are accommodated in the accommodating portion of the case 104 having the upper surface opening type. The housing portion of the case 104 is filled with a mold resin 105 to protect the metallized film capacitor element from the external environment.

  In this conventional case mold type capacitor 101, the case mold type capacitor 101 thus configured is further accommodated in a metal case (not shown), and other components (not shown) separately accommodated in the metal case. Is a general usage method. In such a usage method, the external connection terminal portions 102a and 103a drawn from the case 104 and other components are connected in a metal case.

  However, as shown in FIG. 7A, the bus bars 102 and 103 are pulled out from the opening on the upper surface of the case 104, and depending on the connection position of the other parts, the connection distance to the other parts May be longer. For example, when other parts are arranged on the side of the case 104, the bus bars 102b and 103b drawn from the upper surface opening of the case 104 are arranged on the side of the case 104 as shown in FIG. I have to go further. As described above, when the connection distance is increased, not only the amount of material used is increased, but there is a problem that ESR (equivalent series resistance) and ESL (equivalent series inductance) increase due to an increase in unnecessary resistance.

  For this problem, Patent Document 2 has taken the following measures. FIG. 8 shows a configuration of a case mold type capacitor 201 described in Patent Document 2.

  As shown in FIG. 8, in the case mold type capacitor 201 described in Patent Document 2, a part of the side surface of the case 203 filled with a metallized film capacitor element (not shown) and a mold resin 202 is cut out. And the bus bar 204 is pulled out of the case 203 through the notch. Further, the notch is sealed with a sealing plate 205 that is separate from the case 203.

  In this manner, by using the sealing plate 205 to draw the bus bar 204 from the side surface of the case 203, the technique disclosed in Patent Document 2 does not require the bus bar 204 to be routed from the upper surface opening of the case 203. And other parts can be connected, and the bus bar 204 and other parts can be connected at the shortest distance.

JP 2009-105108 A JP 2010-182914 A

  Certainly, according to the technique described in Patent Document 2, it is possible to connect the bus bar 204 to other components at the shortest distance, and the increase in ESR and ESL can be suppressed.

  However, a new problem has occurred due to the structure in which the notch provided on the side surface of the case 203 is sealed with a sealing plate 205 that is separate from the case 203.

  That is, when the mold resin 202 is poured into the case 203, the mold resin 202 may enter a slight gap between the cutout portion of the case 203 and the sealing plate 205, and may leak out of the case 203. there were.

  If the mold resin 202 leaks out of the case 203 in this way, it takes time to wipe off the leaked mold resin 202 and not only the productivity of the case mold type capacitor 201 is deteriorated, but also metallization. Since the amount of the mold resin 202 covering the film capacitor element is reduced, there is a possibility that the external environmental performance of the case mold type capacitor 201 is adversely affected.

  Further, the leaked mold resin adheres to the bus bar 204 which is an electrode function, so that the contact property between the bus bar 204 and other components is deteriorated, which may adversely affect the capacitor performance.

  Therefore, the present invention provides a highly reliable case mold type capacitor that suppresses leakage of mold resin to the outside during the production of the case mold type capacitor having a structure in which the bus bar is pulled out from the side surface of the case. Objective.

  In order to solve the above problems, a case mold type capacitor according to the present invention includes an element having a pair of electrodes on both end faces, and a pair of bus bars connected to the electrodes of the element and having a terminal portion for external connection. And a case in which a part of the element and the pair of bus bars are housed inside in a resin-molded state, and a part of the side surface has a notch part extending downward from the upper end, and a notch part of the case A terminal plate for external connection of the bus bar is drawn out to the outside of the case through the sealing plate, and the sealing plate and the case are connected to the side of the sealing plate. It is the structure joined by fitting the unevenness | corrugation provided in the contact part of the part and the notch part of the said case.

  With this configuration, it is possible to suppress the leakage of the mold resin to the outside of the case when the case mold type capacitor is manufactured.

  This is because the notch portions of the sealing plate and the case are joined by fitting the unevenness provided at the contact portion between the sealing plate side portion and the case.

  That is, by fitting the concaves and convexes, the sealing plate and the case can be more firmly coupled, and the leakage route of the mold resin can be complicated, so that leakage to the mold resin can be suppressed.

  Furthermore, the fact that the sealing plate can be accurately positioned with respect to the case cut-out portion by concavity and convexity also contributes to the suppression of this mold resin leakage.

  Thus, according to the present invention, it is possible to suppress the possibility that the mold resin leaks to the outside during the production, and it is possible to provide a highly reliable case mold type capacitor.

The perspective view which shows the structure of the metallized film capacitor | condenser element of the case mold type capacitor | condenser of this invention It is a figure which shows the structure of the bus bar of the case mold type capacitor | condenser of this invention, (a) is a perspective view of one bus bar, (b) is a perspective view of the other bus bar. The perspective view which shows the structure of the metallized film capacitor | condenser element of the case mold type capacitor | condenser of this invention, and a bus-bar The perspective view which shows the structure of the case mold type capacitor | condenser of this invention The enlarged top view which shows the structure of the fitting part of the case mold type capacitor of this invention The perspective view which shows the structure of the case mold type capacitor | condenser of this invention It is a figure which shows the structure of the conventional case mold type | mold capacitor, (a) is a perspective view of the conventional case mold type capacitor, (b) is the perspective view which shows the structure which deform | transformed the shape of the bus bar of the conventional case mold type capacitor. Figure Perspective view of a conventional case mold type capacitor

(Embodiment 1)
Hereinafter, the configuration of the case mold type capacitor according to the present embodiment will be described with reference to FIGS.

  1 is a perspective view showing a configuration of a metallized film capacitor element 1 according to the present embodiment, FIG. 2 is a perspective view showing a configuration of bus bars 2 and 3 according to the present embodiment, and FIG. 3 is a metallization according to the present embodiment. FIG. 4 is a perspective view showing a configuration of the case mold type capacitor 10 of the present embodiment. FIG. 4 is a perspective view showing a state where the film capacitor element 1 and the bus bars 2 and 3 are connected.

  As shown in FIG. 1, the metallized film capacitor element 1 used in the present embodiment has a pair of metallized films in which metal vapor-deposited electrodes are formed on one or both sides of a dielectric film made of polypropylene film or the like. After the vapor deposition electrode is wound in a state of being opposed to each other through the dielectric film, it is formed by pressing in a flat shape from the vertical direction. Further, the metallized film capacitor element 1 is provided with metallized electrodes 1a and 1b sprayed with zinc on both end faces, respectively. The metallized electrodes 1a and 1b serve as a pair of extraction electrodes of P and N poles. .

  The bus bar 2 and the bus bar 3 shown in FIGS. 2A and 2B are respectively connected to the metallicon electrodes 1a and 1b of the metallized film capacitor element 1 shown in FIG.

  First, the bus bar 2 that electrically pulls out the metallicon electrode 1a to the outside will be described with reference to FIG.

  The bus bar 2 includes an electrode connecting portion 2a that is directly connected to the metallicon electrode 1a of the metallized film capacitor element 1, a first terminal portion 2b that is connected to an external device (not shown), and a second terminal portion. 2c is integrally formed of a single copper plate.

  The electrode connecting portion 2a has an L-shaped cross section in which a rectangular flat plate is bent approximately 90 degrees in the center in the short direction, and the inner half surface bent into an L shape is metallized. The metal capacitor electrode 1a of the film capacitor element 1 is contacted. In the present embodiment, as will be described later, the metallicon electrodes 1a of a plurality of metallized film capacitor elements 1 are connected to the electrode connection portion 2a.

  The 1st terminal part 2b is a terminal part for external connection connected with an external apparatus, and has comprised flat form. An electric current from the outside flows to the metallized film capacitor element 1 through the first terminal portion 2b. For electrical connection with an external device, a bolt (not shown) is inserted into a through hole 2d provided in the center of the first terminal portion 2b, and the first terminal portion 2b and the external device are connected using this bolt. This is done by fastening the connecting part together.

  On the other hand, the second terminal portion 2c has a flat plate shape that is relatively narrower and longer than the first terminal portion 2b. The second terminal portion 2c is also a terminal portion for external connection connected to an external device. A small current is passed from the bus bar 2 to the external device, and the voltage applied to the metallized film capacitor element 1 is measured. Is for. A part of the second terminal part 2c is provided with a bent part 2e raised upward by being bent. The reason for providing the bent portion 2e will be described later.

  Next, the bus bar 3 that electrically pulls out the N pole 1b to the outside will be described with reference to FIG.

  The electrode connecting portion 3a has an L-shaped cross section in which a rectangular flat plate is bent at approximately 90 degrees in the center in the short direction, and the half surface bent into an L shape is metallized. The metal capacitor electrode 1b of the film capacitor element 1 is contacted. Similar to the electrode connection portion 2a described above, in the present embodiment, the metal connection electrodes 1b of the plurality of metallized film capacitor elements 1 are connected to the electrode connection portion 3a.

  The 1st terminal part 3b is a terminal part for external connection connected with an external apparatus, and has comprised flat form. An electric current from the outside flows to the metallized film capacitor element 1 through the first terminal portion 3b. For electrical connection with an external device, a bolt is inserted into a through hole 3d provided in the center of the first terminal portion 3b, and the first terminal portion 3b and the connection portion of the external device are jointly used with this bolt. Done by tightening.

  On the other hand, the second terminal portion 3c has a flat plate shape that is relatively narrower than the first terminal portion 3b. The second terminal portion 3c is also a terminal portion for external connection connected to an external device. A small current is passed from the bus bar 3 to the external device, and the voltage applied to the metallized film capacitor element 1 is measured. Is for.

  These bus bars 2 and 3 are connected to a plurality of metallized film capacitor elements 1 as shown in FIG. In this embodiment, two metallized film capacitor elements 1 are connected in parallel by bus bars 2 and 3.

  The electrode connecting portion 2a of the bus bar 2 is arranged along the L-shaped portion on the upper end of one end surface of the metallized film capacitor element 1, and is connected to the metallicon electrode 1a. The electrode connecting portion 3a of the bus bar 3 is arranged along the L-shaped portion on the other end surface of the metallized film capacitor element 1 and connected to the metallicon electrode 1b.

  As shown in FIG. 3, when the bus bars 2 and 3 are connected to the metallized film capacitor element 1, the first terminal portions 2b and 3b of the bus bars 2 and 3 are both flat (metal) It becomes perpendicular to the flat portion of the side surface of the fluorinated film capacitor element 1.

  Further, the tips of the second terminal portions 2c and 3c of the bus bars 2 and 3 are arranged so as to be adjacent to each other in the state shown in FIG. The bent portion 2e of the second terminal portion 2c is in a state of straddling the electrode connecting portion 3a so as not to contact the electrode connecting portion 3a of the bus bar 3 as shown in FIG. Thus, by providing the bent part 2e, the bus bar 2 and the bus bar 3 are prevented from being conducted and short-circuited.

  The two metallized film capacitor elements 1 are accommodated in the case 4 shown in FIG. 4 with the bus bars 2 and 3 connected.

  The case 4 has a box shape with an open top surface, and the metallized film capacitor element 1 is accommodated in the accommodating portion 4a. This case 4 is made of resin, and in particular in the present embodiment, case 4 is made of polyphenylene sulfide (PPS).

  Here, as shown in FIG. 4, the tips of the second terminal portions 2c and 3c of the bus bars 2 and 3 are in a state of penetrating the sealing plate 5 formed of PPS. The operation of attaching the sealing plate 5 to the tips of the second terminal portions 2 c and 3 c is performed in advance before the metallized film capacitor element 1 is accommodated in the case 4. That is, after the sealing plate 5 is attached to the tips of the second terminal portions 2c and 3c, the metallized film capacitor element 1 is accommodated in the housing portion so that the sealing plate 5 forms part of the side surface of the case 4. 4a. As a method of attaching the sealing plate 5 to the second terminal portions 2c and 3c, the second terminal portions 2c and 3c may be inserted into the through holes provided in the sealing plate 5 in advance. The sealing plate 5 may be mounted in a state of being substantially integrated with the second terminal portions 2c and 3c by molding.

  The sealing plate 5 is coupled to the case 4 so as to form a part of the side surface of the case 4. That is, as shown in FIG. 4, a part of the side surface of the case 4 is a cutout portion 6 cut out in a rectangular shape from the upper end to the vicinity of the lower end portion, and the sealing plate 5 is appropriately attached to the cutout portion 6. Inserted and joined. Further, the periphery of the notch 6 is formed to be slightly thick so that it can be coupled to the sealing plate 5. The thickness around the notch 6 formed slightly thicker is the same as the thickness of the sealing plate 5.

  The coupling between the sealing plate 5 and the cutout portion 6 of the case 4 is performed by fitting unevenness provided at the contact portion between the sealing plate 5 and the cutout portion 6.

  The connection between the sealing plate 5 and the notch 6 will be described in detail below.

  As shown in FIG. 4, a convex portion 7 projecting outward in an arc shape is provided on the side of the sealing plate 5. Here, the side part of the sealing plate 5 is a part including four surfaces of the six surfaces of the sealing plate 5 excluding two surfaces through which the second terminal portions 2c and 3c of the bus bars 2 and 3 penetrate. is there. The convex portion 7 is formed on three surfaces excluding the upper surface in FIG. 4 among the four surfaces constituting the side portion of the sealing plate 5 (that is, provided on one lower surface not shown). ing). Further, the convex portion 7 is formed from the upper end to the lower end of the sealing plate 5.

  On the other hand, the notch 6 is provided with an arc-shaped recess 8 at a position corresponding to the protrusion 7 of the sealing plate 5. The concave portion 8 is also formed from the upper end to the lower end of the cutout portion 6 in the same manner as the convex portion 7.

  Then, the sealing plate 5 is fitted into the cutout portion 6 from the upper side to the lower side in FIG. 4, and the convex portion 7 of the sealing plate 5 is fitted into the concave portion 8 of the cutout portion 6. 5 and the notch 6 are combined.

  Here, the state of the convex part 7 and the concave part 8 after joining the sealing plate 5 to the notch part 6 is shown in FIG. That is, FIG. 5 is an enlarged view of a portion surrounded by a dotted line in FIG.

  As shown in FIG. 5, the sealing plate 5 and the notch 6 are joined by fitting the convex portion 7 into the concave portion 8. Further, the convex portion 7 has a rib 7a at the apex portion of the arc of the convex portion 7 and ribs 7b, 7c and three ribs on both sides near the root of the arc of the convex portion 7, and the surface of the convex portion 7 is slightly outside. Projecting toward The ribs 7a, 7b, and 7c are formed from the upper end to the lower end of the convex portion 7 of the sealing plate 5.

  On the other hand, the recesses 8 are not provided with recesses corresponding to the ribs 7a, 7b, 7c. That is, when the protrusions 7 are fitted into the recesses 8, the ribs 7a, 7b, 7c are press-fitted into the recesses 8. Will be. As a result, the ribs 7a, 7b, and 7c are in a state of slightly biting into the wall surface of the recess 8, and after the sealing plate 5 is coupled to the notch 6, the vicinity of the ribs 7a, 7b, and 7c It is in a state where a strong pressure is applied compared to the part.

  The ribs 7a, 7b, 7c are not provided on the convex portion 7 on the lower surface shown in FIG. It was provided on the convex portion 7 of the surface.

  Then, the mold resin 9 is injected from the upper surface opening of the case 4 in the state of FIG. 4 and solidified to complete the case mold type capacitor 10 of the present embodiment shown in FIG. As shown in FIG. 6, the case mold type capacitor 10 of the present embodiment is filled with the housing portion 4 a so that the mold resin 9 covers a part of the metallized film capacitor element 1 and the bus bars 2, 3. From the resin 9, the first terminal portions 2 b and 3 b of the bus bars 2 and 3 are exposed upward and pulled out to the outside. Further, from the side surface of the case 4, the tips of the second terminal portions 2 c and 3 c of the bus bars 2 and 3 are drawn out to the outside through the sealing plate 5.

  The case mold type capacitor 10 is used by connecting the first terminal portions 2b and 3b and the second terminal portions 2c and 3c to other components.

  Hereinafter, effects of the configuration of the case mold type capacitor 10 of the present embodiment will be described.

  As shown in FIG. 4 and FIG. 5, the case mold type capacitor 10 of the present embodiment is fitted with unevenness provided on the side of the sealing plate 5 and the contact portion of the notch 6 of the case 4. . Thus, by inserting the sealing plate 5 into the cutout portion 6 and sealing the housing portion 4a of the case 4, the second terminal portions 2c and 3c of the bus bars 2 and 3 are pulled out from the side surface of the case 4 to the outside. At the same time, it is possible to prevent the mold resin 9 from leaking to the outside through a slight gap between the sealing plate 5 and the cutout portion 6 when the accommodating portion 4 a is filled with the mold resin 9.

  That is, by fitting the unevenness, the positioning accuracy of the sealing plate 5 and the notch 6 is improved, and the accommodating portion 4a can be sealed with the sealing plate 5 at an accurate position. This is because the leakage route of the mold resin 9 can be lengthened and complicated. Further, the connection between the case 4 and the sealing plate 5 is also strong due to the uneven fitting. As a result, the possibility of leakage of the mold resin 9 to the outside can be remarkably suppressed.

  In the present embodiment, the convex portion 7 is provided on the side portion of the sealing plate 5 and the concave portion 8 is provided in the notch portion 6, and the convex portion 7 and the concave portion 8 are fitted. The positional relationship between the recesses 8 may be reversed. That is, it is good also as a structure which provided the recessed part in the side part of the sealing board 5, and provided the convex part in the notch part 6. FIG. Moreover, the convex part 7 and the recessed part 8 may be provided with two or more without being restricted to one, For example, it is good also as a wavy line-shaped fitting part by providing two or more. Even if it is such a structure, the effect similar to the case mold type capacitor | condenser 10 of this Embodiment can be acquired.

  Furthermore, in the case mold type capacitor 10 of the present embodiment, ribs 7 a, 7 b, 7 c that are press-fitted when the sealing plate 5 is inserted into the notch 6 are integrally provided on the sealing plate 5.

  As described above, the ribs 7a, 7b, and 7c are press-fitted so as to bite into the wall surface of the recess 8 of the notch 6, so that the mold resin 9 is placed in a slight gap between the sealing plate 5 and the notch 6. Even if it penetrates, the progress of leakage to the outside of the mold resin 9 can be stopped by these ribs 7a, 7b, 7c. Therefore, the provision of these ribs 7a, 7b, 7c further suppresses the possibility of leakage of the mold resin 9 in the case mold type capacitor 10 of the present embodiment.

  In the case mold type capacitor 10 of the present embodiment, the ribs 7a, 7b, 7c are provided on the convex portion 7 side. However, the surface of the concave portion 8 of the notch portion 6 is slightly projected, and the rib is formed on the concave portion 8 side. It is good also as a structure which provided.

  Further, in the case mold type capacitor 10 of the present embodiment, the convex portion 7 has an arc shape. If the convex portion 7 is not a circular arc shape but a rectangular shape or the like, a portion that is locally stressed by the pressure received by the case 4 from the ribs 7a, 7b, 7c (for example, bending of the rectangular concave portion 7) It is also conceivable that the case 4 is damaged and the case 4 is damaged. It is also conceivable that the case 4 is damaged when the mold resin 9 is expanded by receiving heat from the outside. For this reason, in case mold type capacitor 10 of this embodiment, convex part 7 is made into an arc shape, the pressure concerning case 4 is distributed, and the possibility of breakage is controlled.

  As described above, according to the present invention, since the possibility of leakage of the mold resin 9 to the outside when the mold resin 9 is filled with the case mold capacitor 10 can be suppressed, the case mold capacitor 10 is reliable. It has become a high thing.

  In the description of the case mold type capacitor 10, terms indicating directions such as “upward” and “downward” indicate relative directions that depend only on the relative positional relationship of the constituent members, and are vertical and horizontal. It does not indicate an absolute direction such as a direction. Therefore, when the case mold type capacitor 10 is actually used, it is not always necessary to arrange the opening of the case 4 so as to be vertically upward as shown in FIG. 6, for example, vertically downward or horizontally. You may arrange | position so that it may face.

  The present invention is not limited to the configuration of the case mold type capacitor 10 of the above-described first embodiment, and can be implemented with various modifications within the scope of the invention. For example, in the case mold type capacitor 10 of the first embodiment, the second terminal portions 2 c and 3 c for measuring the applied voltage of the metallized film capacitor element 1 are made to penetrate the sealing plate 5. Of course, depending on the specifications of the bus bars 2 and 3, the terminal portions other than the second terminal portions 2 c and 3 c may be penetrated. That is, the bus bar having only the first terminal portions 2b and 3b for passing the current from the outside to the metallized film capacitor element 1 without the second terminal portions 2c and 3c is provided on the side of the case mold type capacitor. The present invention can also be applied to the case where it is desired to pull out the image.

  The case mold type capacitor according to the present invention can suppress the possibility of leakage of the mold resin to the outside of the case at the time of production, and has high reliability. Therefore, it can be suitably used as a capacitor for a hybrid vehicle that is used in various external environments and requires high reliability.

DESCRIPTION OF SYMBOLS 1 Metallized film capacitor | condenser element 1a, 1b Metallicon electrode 2, 3 Bus bar 2a, 3a Electrode connection part 2b, 3b 1st terminal part 2c, 3c 2nd terminal part 2d, 3d Through-hole 2e Bending part 4 Case 5 Sealing Plate 6 Notch 7 Projection 7a, 7b, 7c Rib 8 Concave 9 Mold resin 10 Case mold type capacitor

Claims (3)

An element provided with a pair of electrodes on both end faces;
A pair of bus bars connected to the electrodes of the element and having a terminal portion for external connection;
A case having a notch portion that extends downward from the upper end in a part of the side surface, while accommodating the element and a part of the pair of bus bars in a resin-molded state,
A sealing plate fitted into the notch of the case,
The terminal portion for external connection of the bus bar is pulled out of the case through the sealing plate,
A case mold type capacitor in which the sealing plate and the case are coupled by fitting arc-shaped irregularities provided at a contact portion between the sealing plate side portion and the cutout portion of the case. The case mold type capacitor according to claim 1, wherein a rib for press-fitting is further provided on a convex portion provided on either the sealing plate or the case. The case mold type capacitor according to claim 1, wherein a press-fitting rib is further provided in a recess provided in either the sealing plate or the case.

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