JP2008251595A - Case-mold capacitor and inspection method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a case-mold capacitor preventing the absorption properties of a surge voltage from deteriorating due to a decrease in impedance for the case-mold capacitor used for an automobile, or the like. <P>SOLUTION: First and second capacitors having different resonance frequencies are connected by a bus bar and are stored in a case 6 for molding with resin; the second capacitor is arranged at the side of a terminal section for external connection provided at one end of the bus bar; the N and P poles of the first/second capacitors are connected by a common bus bar 3 and two independent bus bars 4, 5, respectively; and the width of terminal sections 3a, 5a in the bus bars 3, 5 connected to the second capacitor is made at least two times larger than that of external connection sections 3b, 5b at the tip of the terminal section. As a result, input and output currents cancel each other in the wide terminal sections 3a, 5a for canceling inductance, thus reducing impedance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is used in various electronic equipment, electrical equipment, industrial equipment, automobiles, and the like. The present invention relates to a molded case mold type capacitor and an inspection method thereof.

  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 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.

  FIG. 5 is an exploded perspective view showing the structure of this type of conventional case mold type capacitor. In FIG. 5, 10 indicates a metallized film capacitor (hereinafter referred to as a capacitor), and the capacitor 10 is made of polypropylene. A pair of metallized films with metal-deposited electrodes formed on one or both sides of the dielectric film are wound with the metal-deposited electrodes facing each other across the dielectric film to form metallized electrodes with thermal spraying of zinc on both end faces By doing so, a pair of extraction electrodes of P and N poles are provided.

  Reference numeral 11 denotes a P-pole bus bar, and 11a denotes a P-pole terminal for external connection provided at one end of the P-pole bus bar 11. The P-pole bus bar 11 includes a plurality of capacitors 10 in close contact with each other. The P electrode 10 is joined to a P electrode formed on one end face, and the P electrode terminal 11a is pulled out above the capacitor 10 and exposed from a case 13 described later.

  Reference numeral 12 denotes an N-pole bus bar, and 12a denotes an N-pole terminal for external connection provided at one end of the N-pole bus bar 12. The N-pole bus bar 12 also includes a plurality of capacitors 10 in the same manner as the P-pole bus bar 11. The N pole electrodes formed on the other end face of each capacitor 10 are joined in close contact with each other, and the N pole terminal 12a is pulled out above the capacitor 10 and exposed from a case 13 described later. Thus, a plurality of capacitors 10 are connected in parallel connection by the P-pole bus bar 11 and the N-pole bus bar 12.

  Reference numeral 13 denotes a resin case, and reference numeral 14 denotes a mold resin filled in the case 13. The mold resin 14 is connected in parallel by the P-pole bus bar 11 and the N-pole bus bar 12. Is molded into the case 13 by resin molding.

  The conventional case mold type capacitor configured as described above is a highly reliable case mold type excellent in mechanical strength, heat resistance and water resistance by molding the capacitor 10 in the case 13 with the mold resin 14. Capacitors could be provided.

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 conventional case mold type capacitor, the capacitor 10 accommodated in the case 13 is connected to the P pole terminal 11a and the N pole terminal 12a for external connection provided in the P pole bus bar 11 and the N pole bus bar 12, respectively. A smoothing capacitor for smoothing the voltage of the power converter (not shown) is mainly used.

  In some cases, the smoothing capacitor and the snubber capacitor for absorbing the surge voltage generated by the power converter are used in combination. These two types of capacitors are shown in the impedance frequency characteristic diagram of FIG. Thus, the resonance frequencies are different from each other, and the resonance frequency f2 of the snubber capacitor is one digit or more higher than the resonance frequency f1 of the smoothing capacitor.

  In such a case mold type capacitor using a combination of two types of capacitors having different resonance frequencies, if the impedance of the resonance frequency f2 of the snubber capacitor is not lowered in order to increase the absorbability of the surge voltage, it will be used for the snubber. There is a problem that the surge voltage absorbability of the capacitor cannot be improved.

  In addition, in case mold type capacitors using a combination of different types of capacitors, it is not possible to inspect each different type of capacitor independently in the finished product inspection after the mold resin is filled and assembled. There was also a problem.

  The present invention solves such a conventional problem, and even when two types of capacitors having different resonance frequencies are used in combination, a case mold having a low impedance frequency characteristic that can exhibit excellent surge voltage absorbability. An object of the present invention is to provide an inspection method capable of independently inspecting different types of capacitors while providing a type capacitor.

  In order to solve the above problems, the present invention provides a first metallized film capacitor having a resonance frequency (f1) and a second metallization having a resonance frequency (f2) that is 10 times or more of the resonance frequency (f1). A case-molded capacitor in which a film capacitor is connected by a bus bar, and this is accommodated in a case and resin-molded. The second metallized film capacitor is provided on one end of the bus bar on the terminal portion for external connection. In addition, one pole of the first / second metallized film capacitor is connected by a common bus bar, and the other pole is connected by two independent bus bars, and connected to the second metallized film capacitor. The width of the terminal portion of the bus bar is set to be twice or more the width of the external connection portion provided at the tip of the terminal portion.

  In addition, as a method for inspecting the case mold type capacitor, a common bus bar connected to one pole of different first / second metallized film capacitors and an independent connection connected to the other pole are used. The first and second metallized film capacitors are individually inspected through external connection terminal portions provided at one ends of the two bus bars, respectively.

  As described above, the case mold type capacitor according to the present invention has the width of the terminal portion of the bus bar connected to the second metallized film capacitor being at least twice the width of the external connection portion provided at the tip of the terminal portion. With this configuration, the current on the input side that flows to the terminal portion via the external connection portion of the bus bar and the current on the output side that flows from the terminal portion to the external connection portion cancel each other out in the wide terminal portion. Therefore, the inductance is canceled and the impedance can be reduced thereby.

  Also, a common bus bar connected to one pole of the first and second metallized film capacitors of different types, and an external provided at one end of two independent bus bars connected to the other pole, respectively. The effect that each of the first and second metallized film capacitors can be independently inspected via the terminal portion for connection is obtained.

(Embodiment 1)
Hereinafter, the invention described in the entire claims of the present invention will be described using the first embodiment.

  1 is a perspective view before resin molding showing the configuration of a case mold type capacitor according to Embodiment 1 of the present invention, FIG. 2 is a perspective view with the case of FIG. 1 removed, and FIG. 3 is an exploded perspective view of FIG. FIG.

  1-3, 1 is a smoothing metallized film capacitor as a first metallized film capacitor having a resonance frequency (f1), and 2 is a second metallized film capacitor having a resonance frequency (f2). Metallized film capacitors for snubbers (hereinafter referred to as first / second capacitors), and the resonance frequencies (f1), (f2) of the first / second capacitors 1, 2 are ( f2)> 10 (f1).

  Each of the first and second capacitors 1 and 2 is 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, and the metal vapor-deposited electrodes are interposed via the dielectric film. In this state, a pair of extraction electrodes of P and N poles are provided by forming metallicon electrodes each coated with zinc and sprayed with zinc on both end faces. Three capacitors 1 and one second capacitor 2 are provided in a straight line (the number of capacitors is not limited to this).

  3 is an N pole bus bar, 3a is an N pole terminal portion for external connection provided at one end of the N pole bus bar 3, and 3b is an external connection portion provided at the tip of the N pole terminal portion 3a (with an external device). The width of the N pole terminal portion 3a is formed to be twice or more the width W of the external connection portion 3b. The N-pole bus bar 3 has the N-pole electrodes of the first and second capacitors 1 and 2 (in FIG. 1 to FIG. 3) with the second capacitor 2 disposed on the N-pole terminal portion 3a side. This is a common bus bar that is connected together.

  Reference numeral 4 denotes a first P-pole bus bar, 4a denotes an external connection P-pole terminal provided at one end of the first P-pole bus bar 4, and 4b denotes an external connection provided at the tip of the P-pole terminal 4a. Part (similar to the external connection part 3b), and the first P-pole bus bar 4 integrally connects the P-pole electrodes (front side in FIGS. 1 to 3) of the plurality of first capacitors 1. An independent bus bar.

  Reference numeral 5 denotes a second P-pole bus bar, 5a denotes an external connection P-pole terminal provided at one end of the second P-pole bus bar 5, and 5b denotes an external connection provided at the tip of the P-pole terminal 5a. The width of the P-pole terminal portion 5a is more than twice the width W of the external connection portion 5b. The second P-pole bus bar 5 is an independent bus bar connected to the P-pole electrode (front side in FIGS. 1 to 3) of the second capacitor 2.

  Further, the P-pole terminal portion 4a of the first P-pole bus bar 4 and the P-pole of the second P-pole bus bar 5 are sandwiched between insulating materials (not shown) before and after the N-pole terminal portion 3a of the N-pole bus bar 3, respectively. The electrode terminals 5a are respectively arranged, whereby the first and second capacitors 1 and 2 are integrally connected in a parallel connection state, and the P electrode side external connection parts 4b, 5b, and It is configured to be connected to an external device (not shown) via the N pole side external connection portion 3b.

  Reference numeral 6 denotes a resin case. In the case 6, a plurality of first / second electrodes connected together by the N pole bus bar 3, the first P pole bus bar 4, and the second P pole bus bar 5 are integrated. After the capacitors 1 and 2 are accommodated, the case 6 is filled with an insulating mold resin (not shown) in the case 6 to constitute the case mold type capacitor according to the present embodiment.

  Further, in the state where the mold resin (not shown) is filled, a part of the N pole bus bar 3 and the N pole terminal part 3a, a part of the first P pole bus bar 4 and the P pole terminal part 4a, a second P pole A part of the bus bar 5 and the P pole terminal part 5a are embedded in the mold resin, a part of the N pole terminal part 3a and the external connection part 3b, a part of the P pole terminal part 4a, the external connection part 4b, and the P pole terminal. Part of the part 5a and the external connection part 5b are configured to be exposed from the mold resin.

  The case mold type capacitor according to the present embodiment configured as described above includes the P pole terminal portion 5a of the second P pole bus bar 5 and the N pole bus bar 3 connected to the snubber capacitor as the second capacitor 2. The width of the N pole terminal portion 3a is set to be twice or more the width of the external connection portions 5b and 3b provided at the respective tips of these terminal portions, and the N pole electrodes of the first and second capacitors 1 and 2 P pole terminal portion 4a of the first P pole bus bar 4 connected to the P poles of the first and second capacitors 1, 2 before and after the N pole terminal portion 3a of the common N pole bus bar 3 connected to The configuration in which the P-pole terminal portions 5a of the second P-pole bus bar 5 are arranged, respectively, causes the current on the input side to flow to the terminal portion via the external connection portion of each bus bar and the output to flow from the terminal portion to the external connection portion. Side currents in the wide terminal area. Inductance is canceled because it flows in a mutually flowing manner, which makes it possible to reduce the impedance, and it is possible to improve the absorbability of the surge voltage of the snubber capacitor compared to the conventional case. This is a special effect.

  In addition, a smoothing capacitor as the first capacitor 1 is obtained after the assembly as a case mold type capacitor is completed by dividing the P pole bus bar connected to the P pole electrodes of the first and second capacitors 1 and 2. Even if the capacitance value of the snubber capacitor as the second capacitor 2 is different by 100 times or more, it is possible to grasp the correct value by inspecting each of them independently. Is.

(Embodiment 2)
Hereinafter, the second embodiment will be used to describe the invention described in the entire claims.

  In the present embodiment, the configuration of the bus bar on the P pole side of the case mold type capacitor described in the first embodiment with reference to FIGS. 1 to 3 is partially different. Since they are the same as those of the first embodiment, the same portions are denoted by the same reference numerals and detailed description thereof is omitted, and only different portions will be described below with reference to the drawings.

  4 is a perspective view of a main part before resin molding showing the configuration of the case mold type capacitor according to the second embodiment of the present invention. In FIG. 4, 7 is an N pole bus bar, 7a is one end of the N pole bus bar 7. FIG. N pole terminal portion 7b for external connection provided on the outside, 7b is an external connection portion provided at the tip of this N pole terminal portion 7a, and this N pole bus bar 7 is the N pole bus bar described in the first embodiment. 3 is a common bus bar which is formed in the same manner as No. 3 and integrally connects the N-pole electrodes (back side in FIG. 4) of the first and second capacitors 1 and 2.

  Reference numeral 8 denotes a first P-pole bus bar, and 8a denotes a connecting portion provided at one end of the P-pole bus bar 8. The first P-pole bus bar 8 is a P-pole electrode of a plurality of capacitors 1 (the front side in FIG. 4). ) Is an independent bus bar connected together.

  9 is a second P pole bus bar, 9a is a P pole terminal portion for external connection provided at one end of the second P pole bus bar 9, and 9b is an external connection provided at the tip of the P pole terminal portion 9a. 9c is a connecting portion, and the second P-pole bus bar 9 is formed in the same manner as the second P-pole bus bar 5 described in the first embodiment except for the connecting portion 9c. It is an independent bus bar connected to the electrode (front side in FIG. 4).

  The case-molded capacitor according to the present embodiment configured as described above has the effects obtained by the case-molded capacitor according to the first embodiment, in addition to the first / second P-connected to the P-pole electrode of the capacitor. The degree of freedom of the division configuration of the pole bus bar can be expanded, and is suitable when the division configuration of the first / second P pole bus bar shown in the first embodiment is not possible. Various configurations other than the embodiment are possible.

  The case mold type capacitor according to the present invention can reduce impedance, improve the absorbability of the surge voltage of the snubber capacitor, and can inspect different types of capacitors independently. It has an effect and is particularly useful as a capacitor in the field of automobiles such as hybrid cars.

The perspective view before the resin mold which showed the structure of the case mold type capacitor | condenser by Embodiment 1 of this invention 1 is a perspective view with the case of FIG. 1 removed. 2 is an exploded perspective view of FIG. The principal part perspective view before the resin mold which showed the structure of the case mold type capacitor by Embodiment 2 of this invention An exploded perspective view showing the configuration of a conventional case mold type capacitor Impedance frequency characteristic diagram of conventional case mold type capacitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor for smoothing 2 Capacitor for snubbers 3, 7 N pole bus bar 3a, 7a N pole terminal part 3b, 4b, 5b, 7b, 9b External connection part 4, 8 First P pole bus bar 4a, 5a, 9a P Polar terminal portion 5, 9 Second P-pole bus bar 6 Case 8a, 9c Connecting portion

Claims (4)

The first metallized film capacitor having the resonance frequency (f1) and the second metallized film capacitor having the resonance frequency (f2) 10 times or more the resonance frequency (f1) are connected to one end of the terminal portion for external connection. A case-molded capacitor which is connected with a bus bar provided in the housing, and is resin-molded by housing it in a case and excluding at least the terminal portion of the bus bar, wherein the second metallized film capacitor is provided at one end of the bus bar. Arranged on the terminal portion side for external connection, and one pole of the first / second metallized film capacitor is connected by a common bus bar, and the other pole is connected by two independent bus bars, and A case module in which the width of the terminal portion of the bus bar connected to the second metallized film capacitor is at least twice the width of the external connection portion provided at the end of the terminal portion. Field type capacitor. Claims in which the terminal portions of two independent bus bars connected to the other pole are respectively arranged before and after the terminal portion of the common bus bar connected to one pole of the first / second metallized film capacitor. Item 2. A case mold type capacitor according to item 1. The case mold type capacitor according to claim 1, wherein the first metallized film capacitor is used for smoothing an inverter, and the second metallized film capacitor is used for a snubber that absorbs a surge voltage. Different types of first and second metallized film capacitors, one pole is connected with a common bus bar and the other pole is connected with two independent bus bars, which are housed in a case and molded with resin. An inspection method for inspecting a case mold type capacitor, wherein the first bus terminal is provided at one end of the common bus bar and two independent bus bars, and is connected to the first via the external connection terminal portion exposed from the mold resin. The method for inspecting a case mold type capacitor according to any one of claims 1 to 3, wherein each of the second metallized film capacitors is inspected independently.

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