JP2009252934A - Case molded capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly accurate, small-sized and lightweight case molded capacitor for use in a hybrid vehicle or the like. <P>SOLUTION: With a structure that a cylindrical collar 5 longer than thickness of a tightening part 4a is arranged within a fitting hole 4b provided to the tightening part 4a of a resin case 4 and the tightening part 4a of the resin case 4 is coupled to a tightening part 7a of a metal case 7 using a bolt, both ends of the collar 5 are placed in contact respectively with the bolt and the tightening part 7a of metal case 7. Therefore, although the tightening part 4a of the resin case 4 is guided with the collar 5, the collar 5 is ready for move in the tightening direction because it is formed in the cylindrical shape. Moreover, even when the resin case 4 is coupled within the metal case 7 fluctuation in size tolerance of both resin case 4 and metal case 7 can be absorbed and higher size accuracy can be attained without generation of distortion in both cases. Accordingly, the small-sized and lightweight capacitor can be obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is used in various electronic equipment, electrical equipment, industrial equipment, automobiles, etc., and in particular, a metallized film capacitor that is optimal for smoothing, filtering, and snubbing of a motor drive inverter circuit of a hybrid car is accommodated in a case. And a resin-molded case mold type capacitor.

  In recent years, from the viewpoint of environmental protection, all electrical 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 such a HEV electric motor has a high operating voltage range of several hundred volts, a metallized film capacitor having high withstand voltage and low loss electric characteristics 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 conspicuous due to the demand for maintenance-free in the market.

  And since the metallized film capacitor used for HEVs in this way is required to have a high withstand voltage, large current, large capacity, etc., a plurality of metallized films connected in parallel by bus bars. A case mold type capacitor in which a capacitor is housed in a case and a mold resin is poured into the case has been developed and put into practical use.

  5A and 5B are a plan sectional view and a front sectional view showing the structure of this type of conventional case mold type capacitor. In FIG. 5, 11 is a resin capacitor case, and 12 is a capacitor element. Indicates. Reference numerals 13a and 13b are integrally connected connecting fittings, 13a is a part built in the capacitor case 11, and 13b is a part protruding from the capacitor case 11 to the outside. Reference numeral 14 denotes a filling resin such as an epoxy resin for fixing the capacitor element 12, 15 denotes an electrode portion, 16 denotes an attachment leg for attaching the capacitor to the outside, and 17 denotes a casting surface for casting the filling resin 14.

  And the said capacitor | condenser element 12 winds or laminates | stacks the metallized film which is not shown in figure, and has provided the electrode part 15 in the end surface. The connection fitting 13a is connected to the electrode portion 15, and the connection fitting 13b (connected integrally with 13a) is electrically connected to an external device or the like.

  The capacitor case 11 includes the entire capacitor element 12 and a connection fitting 13a, and is filled with a filling resin 14 and fixed. In FIG. 5, the bottom portion (casting surface 17) of the capacitor case 11 is an opening surface before resin filling, and this surface is a surface on which the filling resin 14 is cast. Further, the connection fitting 13 b protrudes from the capacitor case 11 to the outside from the casting surface 17.

  Further, as shown in FIG. 5, the capacitor case 11 has an attachment leg 16 so that it can be attached to an external device or the like with a screw or the like. The capacitor case 11 is large in order to incorporate a plurality of capacitor elements 12, and the mounting legs 16 are provided at four locations from the weight of the entire capacitor and the durability in the event of a collision, and have a shape extending in all directions.

  In the conventional case mold type capacitor configured as described above, the casting surface 17 for casting the filling resin 14 is on the same side as the mounting leg 16, and the connection fitting 13 is exposed from the casting surface 17 to the outside. By doing so, the distance until the connection fittings 13a, 13b are connected to an external device or the like can be shortened, whereby the inductance of the connection fittings 13a, 13b can be suppressed. In addition, there has been an increasing number of usage methods in which the case mold type capacitor configured in this manner is coupled to an aluminum exterior case (not shown), and the exterior case is attached to an automobile which is a mounted body. .

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2004-146724 A

  However, in the case of the conventional case mold type capacitor, in the case where the case mold type capacitor resin-molded using the resin capacitor case 11 is used by being bonded to an aluminum outer case (not shown), it is made of resin. The resin-made capacitor case 11 and the aluminum-made outer case are connected to a mounting portion provided in an aluminum-made outer case (not shown) via a mounting leg 16 provided in the capacitor case 11 using bolts or the like. As a result, when the aluminum outer case is attached to the mounted body, it cannot be attached, or the mounting leg 16 provided on the resin capacitor case 11 is overstressed. In the worst case, it will break into the mounting leg 16 due to vibration. There is a problem that may occur.

  In addition to such a phenomenon that the thickness of the aluminum outer case has become thinner due to the pursuit of miniaturization and weight reduction, the mounting portion of the aluminum outer case and the mounting leg 16 of the resin capacitor case 11 This is due to both dimensional tolerances.

  The present invention solves such a conventional problem, and even when the resin case is joined to the metal case, the case does not generate distortion in both cases, and can achieve both high accuracy and small size and light weight. The object is to provide a capacitor.

  In order to solve the above problems, the present invention comprises a resin case in which a plurality of elements are connected by a bus bar, and these are accommodated in a resin mold, and a metal case in which the resin case is coupled to the inside. A tongue-shaped fastening portion is provided, and the fastening portion is placed on the fastening portion provided in the metal case, and the height higher than the thickness of the fastening portion is set in the attachment hole provided in the fastening portion of the resin case. The resin case is coupled to the metal case by screwing a bolt in a state where a metal collar formed in a cylindrical shape with a length is disposed.

  As described above, in the case mold type capacitor according to the present invention, the cylindrical collar having a height dimension longer than the thickness of the fastening portion is disposed in the mounting hole provided in the fastening portion of the resin case, and the resin case is fastened by the bolt. Since the collar is coupled to the fastening portion of the metal case, both ends of the collar come into contact with the bolt and the fastening portion of the metal case, respectively, so that the fastening portion of the resin case is guided by the collar. However, since the collar is cylindrical, it can move in the fastening direction, and even if the resin case is joined in the metal case, it absorbs the variation in dimensional tolerance between the resin case and the metal case. Since no distortion occurs and high dimensional accuracy can be exhibited, an effect that a reduction in size and weight can be achieved can be obtained.

(Embodiment 1)
Hereinafter, the invention described in the first to third aspects of the present invention will be described using the first embodiment.

  1 is a perspective view showing the configuration of a case mold type capacitor according to Embodiment 1 of the present invention, FIG. 2 is a side sectional view of the same, and FIG. 3 is a sectional view of the principal part showing the vicinity of the fastening portion. 3, reference numeral 1 denotes a metallized film capacitor element (hereinafter referred to as element 1). This element 1 is a metallized film in which a metal vapor-deposited electrode is formed on one or both sides of a dielectric film made of polypropylene film or the like. A pair of P electrode and N electrode take-out electrodes are provided by winding a pair of metal vapor deposition electrodes facing each other through a dielectric film, and forming metallized electrodes sprayed with zinc on both end faces. It has been done.

  2 is a P pole bus bar, 2a is a P pole terminal for external connection provided at one end of the P pole bus bar 2, 3 is an N pole bus bar, 3a is an external connection provided at one end of the N pole bus bar 3 This is an N-pole terminal, and the P-pole bus bar 2 and the N-pole bus bar 3 connect a plurality of the elements 1 in parallel.

  4 is a resin case having an open top surface, 4a is a tongue-like fastening portion provided at a plurality of positions on the side surface for coupling the resin case 4 to a metal case 7 to be described later, and 4b is provided in the fastening portion 4a. Mounting holes. Reference numeral 5 denotes a metal collar insert-molded in the mounting hole 4b. The collar 5 has a height dimension (h) longer than the thickness (t) of the fastening portion 4a (that is, h> t). The collar 5 is formed so that both ends of the collar 5 protrude to the upper surface side and the lower surface side of the fastening portion 4a.

  Reference numeral 6 denotes an insulating mold resin made of epoxy resin or the like. The mold resin 6 includes a plurality of elements 1 connected in parallel by the P-pole bus bar 2 and the N-pole bus bar 3 in a resin case 4. In the accommodated state, the resin case 4 is filled and resin-molded, thereby forming a case mold type capacitor in which the P-pole terminal 2a and the N-pole terminal 3a are exposed from the mold resin 6. It is what.

  Reference numeral 7 denotes a metal case made of aluminum. The metal case 7 functions as an exterior case. 7a is a fastening portion provided for joining the resin case 4 in which the plurality of elements 1 are resin-molded in the metal case 7, and 7b is an attachment portion for attaching the metal case 7 to the mounted body. Reference numeral 7c denotes an attachment hole provided in the attachment portion 7b, and the fastening portion 4a of the resin case 4 to the fastening portion 7a provided in the metal case 7 is coupled by screwing a bolt 8. It is.

  The case mold type capacitor according to the present embodiment configured as described above has a cylindrical shape with a height dimension h longer than the thickness t of the fastening portion 4a in the mounting hole 4b provided in the fastening portion 4a of the resin case 4. The collar 5 is disposed, and the fastening portion 4 a of the resin case 4 is coupled to the fastening portion 7 a of the metal case 7 by the bolt 8, so that both ends of the collar 5 are fastened portions 7 a of the bolt 8 and the metal case 7. The fastening portion 4a of the resin case 4 is guided by the collar 5, but the collar 5 is cylindrical, so that it can move in the fastening direction, and the metal case 7 Even if the resin case 4 is coupled, the variation in the dimensional tolerance between the resin case 4 and the metal case 7 is absorbed, and distortion is not generated in both of them, and high dimensional accuracy can be exhibited. Because, in which exhibits the significant effect that by reducing the thickness of the metal case 7 can be reduced in size and weight.

  The collar 5 has a recess formed by applying a groove or the like to the central portion of the outer periphery. By insert molding the collar 5, the resin wraps around the recess and the retaining effect is obtained. However, when such a collar is used, the effect that the fastening portion 4a of the resin case 4 moves in the fastening direction as in the present invention cannot be obtained. It is necessary to use the cylindrical collar 5 as in the invention.

  Such an effect is obtained by the relationship between the outer diameter dimension φA of the collar 5 and the dimension φB of the mounting hole 4b of the fastening portion 4a of the resin case 4 provided so that the collar 5 is fitted. By doing so, the fastening portion 4a of the resin case 4 is easy to move, which is more effective. If the collar 5 cannot be insert-molded by the relationship of φA <φB, the collar 5 is disposed in the mounting hole 4 b provided in the fastening portion 4 a of the resin case 4. It is a good thing.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the second embodiment.

  In the present embodiment, the resin case used in the case mold type capacitor described in the first embodiment with reference to FIGS. 1 to 3 is partially different, and other configurations are the same as those in the embodiment. Since it is the same as that of the first embodiment, the same reference numerals are given to the same parts and the detailed description thereof is omitted, and only different parts will be described in detail with reference to the drawings.

  FIG. 4 is a cross-sectional view of the principal part showing the configuration in the vicinity of the fastening portion of the case mold type capacitor according to Embodiment 2 of the present invention. In FIG. 4, 9 is a resin case with an open top surface, 9a is this resin case 9 The tongue-shaped fastening portions 9b provided at a plurality of positions on the side surface for coupling the metal case 7 to the metal case 7 are mounting holes provided in the fastening portion 9a. 9c is a thin part provided so that a part of the base part by the side of the fastening part 7a of the metal case 7 used as the lower surface of the said fastening part 9a may be made thin partially.

The case mold type capacitor according to the present embodiment configured as described above is provided with the thin wall portion 9c at the base portion of the fastening portion 9a of the resin case 9 in addition to the effect obtained by the case mold type capacitor according to the first embodiment. Since the strength of the fastening portion 9a is weakened by the configuration,
When the resin case 9 is joined to the metal case 7, the fastening portion 9a of the resin case 9 is easy to move in the fastening direction, thereby suppressing excessive stress from being applied to the fastening portion 9a and fastening by vibration. This makes it possible to prevent the portion 9a from being cracked, and to produce a special effect that vibration resistance can be improved.

  The case mold type capacitor according to the present invention has the effect of being able to reduce the size and weight because high dimensional accuracy can be ensured, and particularly for automobiles that are strongly required to be small and light and to have vibration resistance. It is useful as a capacitor of

The perspective view which showed the structure of the case mold type capacitor | condenser by Embodiment 1 of this invention Cross-sectional side view Cross-sectional view of the main part showing the vicinity of the fastening part Sectional drawing which shows the principal part structure which showed the fastening part vicinity of the case mold type capacitor by Embodiment 2 of this invention (A) Plan sectional drawing which showed composition of conventional case mold type capacitor, (b) Front sectional view

Explanation of symbols

1 element 2 P pole bus bar 2a P pole terminal 3 N pole bus bar 3a N pole terminal 4, 9 Resin case 4a, 7a, 9a Fastening portion 4b, 7c, 9b Mounting hole 5 Color 6 Mold resin 7 Metal case 7b Mounting portion 8 Bolt 9c Thin part

Claims (4)

A plurality of elements each provided with a pair of electrodes on both end faces are connected in parallel with each other with a bus bar provided with a terminal portion for external connection at one end, and these are accommodated inside to remove at least the terminal portion of the bus bar. In a case mold type capacitor comprising a resin case molded with a resin and a metal case in which the resin case is coupled, a tongue-like fastening portion is provided on the resin case, and the fastening portion is provided on the metal case. The bolt is placed in a state where a metal collar formed in a cylindrical shape with a height dimension longer than the thickness of the fastening portion is disposed in the mounting hole provided in the fastening portion of the resin case. A case mold type capacitor in which the resin case is joined to a metal case by screwing. 2. The case mold type capacitor according to claim 1, wherein both ends of the metal collar are in contact with bolts and fastening portions provided on the metal case, respectively. 2. The case mold according to claim 1, wherein the relationship between the outer diameter size φA of the metal collar and the mounting hole size φB of the fastening portion of the resin case provided so that the collar is fitted is φA <φB. Capacitor. The case mold type capacitor according to claim 1, wherein a thin-walled portion is provided on a part of a lower surface of a root portion of a tongue-like fastening portion provided in the resin case.

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