Noise proof capacitor unit for a vehicular generator

Abstract: A noise-proof capacitor unit for a vehicular generator comprising an insulator 15 disposed between a positive-side heat sink 13 and a negative-side heat sink 14 of a rectifier for supporting them in an electrically insulating relationship from each other. The insulator 15 has integrally formed therein an insulating receptacle 17 for receiving and supporting therein a capacitor element 11. The capacitor unit also comprises a pair of terminal plates 21, 22 each mounted on the insulator 15 and having one end in electrical contact with the heat sink 13 or 14 and the other end connected to a terminal wire 12a or 12b of the capacitor element.

Description: BACKGROUND OF THE INVENTION This invention relates to a noise proof capacitor unit for mounting to a rectifier of a vehicular generator. Fig. 1 is a sectional view illustrating a manner in which a conventional noise proof capacitor unit is mounted to a rectifier of a vehicular generator. In the figure, the noise proof capacitor 1, together with an insulator 2, is fitted between a heat sink positive side 3 and a heat sink negative side 4 of the rectifier, and the mounting portion 5 of the capacitor 1 is brought in contact with the heat sink negative side 4. Also, the capacitor 1 has a terminal 6 solder-connected to a terminal plate 8 integrally molded within an insulating plate 7 to be brought into contact with the heat sink positive side 3. Also, since an outer cylinder portion 10 of the capacitor 1 is connected to the mounting portion 5 and has a different polarity as that of the terminal 6, an insulating paper 9 is inserted. Thus, both of the terminals of the capacitor 1 are respectively connected to the heat sink positive side 3 and the heat sink negative side 4. Since the conventional noise proof capacitor unit is arranged as above described and the mounting portion 5 and the outer cylinder portion 10 which are one of the terminals are exposed and not insulated, the resistance to environment is poor. Also, the insulating paper 9 is required in order for the insulation between the terminal 6 which is the other terminal and the outer cylindrical portion 10, and the terminal 6 and the terminal plate 8 must be soldered upon the assembly of the rectifier, resulting in a complex structure leading to a troublesome manufacture. Further, the insulator 2 and the mounting portion 5 must be fitted together and placed between the heat sink positive side 3 and the heat sink negative side 4 during the assembly of the rectifier, the assembling efficiency is disadvantageously poor. Accordingly, one of the objects of the present invention is to provide a noise-proof capacitor unit for a vehicular generator free from the above-discussed problems. Another object of the present invention is to provide a noise-proof capacitor unit for a vehicular generator which has a superior resistance to environmental conditions. Another object of the present invention is to provide a noise-proof capacitor unit for a vehicular generator which is simple in structure and easy to manufacture. According to the present invention there is provided a noise-proof capacitor unit for mounting to a rectifier of a vehicular generator, comprising: a capacitor element having a pair of terminals; a positive and a negative heat sink for said rectifier; an insulator disposed between said heat sinks and supporting them in an electrically insulating relationship from each other, said insulator having integrally formed therein an insulating receptacle wherein said capacitor element is arranged; and a pair of terminal plates each mounted on said insulator and each having one end in electrical contact with a respective heat sink and another end connected to a respective terminal of said capacitor element. The capacitor element is held within the insulation and the resistance to environmental conditions is improved. Also, both of the terminals of the capacitor element are connected to the respective terminal plates on the mounting surfaces of the insulator, so that the soldering operation is unnecessary during the assembly of the rectifier. Further, the conventional insulating paper becomes unnecessary. The present invention will become more readily apparent from the following detailed description of the preferred embodiment of the present invention taken in conjunction with the accompanying drawings, in which: Fig. 1 is a vertical sectional front view of the conventional noise-proof capacitor unit for a vehicular generator; Fig. 2 is a vertical sectional front view of the noise-proof capacitor unit for a vehicular generator of the present invention; and Fig. 3 is a plan view of the the noise-proof capacitor unit illustrated in Fig. 3. DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described in conjunction with Figs. 2 and 3. A noise-proof capacitor unit for a vehicular generator comprises a capacitor element 11 having a pair of terminal wires 12a and 12b and a positivie-side rectifier heat sink 13 and a negative-side rectifier heat sink 14. The heat sinks 13 and 14 are tubular in shape. The capacitor unit also comprises an insulator 15 made of an electrically insulating resin material and disposed between the positive-side heat sink 13 and the negative-side heat sink 14 for supporting the heat sinks 13 and 14 in a separated, electrically insulated relationship from each other. The insulator 15 includes a plate-shaped main body 16 having a first end sandwiched between the rectifier heat sinks 13 and 14 and a second end having integrally formed thereon an insulating receptacle 17 in which the capacitor element 11 is received. The space above the capacitor element 11 is filled with a filler resin 18 to seal the opening of the insulating receptacle 17. The main body 16 also has a hollow cylindrical tube 19 extending through the main body 16 in the first end disposed between the heat sinks 13 and 14. The opposite ends of the cylindrical tube 19 projecting from the main body 16 are respectively fitted or inserted into the hollow cylindrical heat sinks 13 and 14 to support them. It is seen that one end (the upper end as viewed in Fig. 2) of the cylindrical tube 19 extends through the heat sink 13 and a ring-shaped insulating plate 20 is attached thereto. On the major surfaces of the insulator main body 16, a first terminal plate 21 and a second terminal plate 22 are securely mounted so that one end of the terminal plates 21 and 22 are brought into an electrical contact with the heat sinks 13 and 14 when the heat sinks 13 and 14 are put in place. The other end of the terminal plates 21 and 22 are bent upwardly at substantially right angles and embedded within the insulating resin material of the insulator 12 to provide tabs 23 and 24 for electrical connection to the terminal wires 12a and 12b, respectively. The construction as above discussed may preferably be obtained by the partial insert-molding of the terminal plates 21 and 22 within the main body 16 of the insulator 12. In the above embodiment, since the capacitor element 11 is protected by being held within the insulating receptacle 17 and is sealed by the filler 18, the resistance to environment is significantly improved. Also, since the insulator 15 may be simply fitted between the positive side heat sink 13 and the negative side heat sink 14 and the both terminals 12a and 12b of the capacitor element 11 are soldered to the tabs 23 and 24 of the terminal plates 21 and 22 prior to the assembly of the rectifier, it is not necessary to carry out soldering during the assembly of the rectifier. Also, it is not necessary to apply an insulating paper which were needed in the prior art capcitor unit to electrically insulate the terminal from the outer casing. Therefore, the capacitor unit of the present invention is simple in structure and easy to manufacture. Further, while the capacitor element 11 is held by a resin filler 20 within the insulating receptacle 17 in the above embodiment, a bonding agent may equally be used to hold and seal the capacitor element 11. Also, either one of the terminal plates 21 and 22 may be formed as a component separable from the insulator 15.

Claims: A noise-proof capacitor unit for mounting to a rectifier of a vehicular generator, comprising: a capacitor element (11) having a pair of terminals (12a, 12b); a positive and a negative heat sink (13, 14) for said rectifier; an insulator (15) disposed between said heat sinks and supporting them in an electrically insulating relationship from each other, said insulator having integrally formed therein an insulating receptacle (17) wherein said capacitor element (11) is arranged; and a pair of terminal plates (21, 22) each mounted on said insulator (15) and each having one end in electrical contact with a respective heat sink (13, 14) and another end connected to a respective terminal (12a, 12b) of said capacitor element (11). A noise-proof capacitor unit as claimed in claim 1, wherein said insulator (15) comprises a plate-shaped main body (16) integrally having one end sandwiched between the rectifier heat sinks and the other end secured to said insulating receptacle (17); and a hollow cylindrical tube (19) extending through said other end of said main body and through said rectifier heat sinks for supporting it; each of said terminal plates being partially insert-molded with said main body of said insulator (16).

Inventors: FUKUSHIMA SUMIO C O HIMEJI SEI, FUKUSHIMA, SUMIO, C/O HIMEJI SEISAKUSHO OF
Applicants: MITSUBISHI ELECTRIC CORP, MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1990
Main classification: H01G2
IPC codes: H02K11, A46B15, H02K19, H01G4