JPS638105Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a resin-clad capacitor having a safety function.

A capacitor made by winding a metallized plastic film or metalized paper to form a capacitor element, housing this capacitor element in a resin case, filling it with resin and sealing it, or a capacitor having a resin molded exterior is a dielectric material. When a part of the film or paper becomes extremely deteriorated, current concentrates on the deteriorated part and flows, raising the temperature of the capacitor element and increasing the gas pressure, destroying the exterior and causing wax and other impregnating agents to scatter. had the disadvantage of causing accidents such as burning of the exterior.

The present invention aims to improve the above-mentioned drawbacks and to provide a resin-clad capacitor that can prevent destruction or combustion of the capacitor element and the exterior.

In order to achieve the above object, the present invention provides, in a resin-clad capacitor, a terminal that is connected to a capacitor element and drawn out from the exterior, an insulating substrate that is connected to the middle of the terminal and insulates and separates the terminal. The object of the present invention is to provide a resin-clad capacitor characterized by having a heat sensing wire connected to the separated portion of the terminal.

Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIG. 1, numeral 1 designates a capacitor element in which metallized plastic film or metallized paper is laminated and wound either alone or together with non-metalized plastic film or non-metalized paper, and metallic contact portions 2a and 2b are provided on both end faces. It is being 3a and 3b
are terminals connected to the metallic contact portions 2a and 2b, and their tips are drawn out to the outside of the resin molded exterior 4. Insulating substrates 5a and 5b are connected to the separated portions of the terminals 3a and 3b and can insulate them. As shown in FIG. 2, the insulating substrates 5a and 5b are approximately 1 mm thick paper-phenol resin laminates, paper epoxy resin laminates, etc. formed into approximately square shapes, with copper foils 6-1 and 6-2
is printed, and the terminal 3 is printed on the copper foils 6-1 and 6-2.
Separate parts a and 3b are connected. 7a and 7b are heat sensing wires that electrically connect the separated parts of the terminals 3a and 3b, and both ends are covered with copper foil 6-
1 and 6-2. Heat sensing wire 7
7a and 7b have a structure in which an electric wire 8 made of a low-melting point metal is covered with a flame-retardant plastic insulator 9 that melts near the melting point of the electric wire 8. In particular, the electric wire 8 is made of a metal with a low melting point of 100° C. to 200° C., and an alloy made of bismuth, tin, lead, etc. is used as an example. Moreover, the plastic insulator 9 is
Base polymers are ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate, ethylene ionomer, etc., and compositions containing decabromdefhenyl ether, ammonium trioxide, etc., and polyvinyl chloride, etc., are flame retardant and do not burn out. A material having a property of melting or a thermoplastic resin such as polyethylene, polystyrene, or polypropylene is used, and the electric wire 8 is coated by molding or the like.

Since the present invention has the above-described configuration, when a voltage is applied to the capacitor 10 from an external circuit,
When part of the dielectric of capacitor element 1 deteriorates,
Current increases through this deteriorated portion. When the flowing current increases, the capacitor element 1 generates heat, which is transmitted to the heat sensing wires 7a and 7b. Heat sensing wire 7
When wires a and 7b are heated to a melting temperature, as shown in FIG. 3, the wire 8 first melts and then the plastic insulator 9 melts and fills the melted portion of the wire 8 to insulate it. In this way, the heat sensing wires 7a and 7b detect abnormal heat generation in the capacitor element 1 and fuse, thereby cutting off the flow of current from the external circuit, preventing heat generation in the capacitor element 1, and preventing combustion. . In addition, capacitor element 1
Since expansion of the internal gas due to heat generation is also prevented, destruction and combustion of the exterior casing 4 are also prevented. Moreover, since the fused portions of the heat sensing wires 7a and 7b are insulated by the melted plastic insulator 9, they will operate reliably without being reconnected.

In addition, when manufacturing the molded capacitor of the above example, the terminals were molded to prevent the capacitor element from shifting from its predetermined position in the mold due to the pressure when injecting the resin into the mold, resulting in uneven thickness of the exterior. According to the present invention, when inserting into a mold, even if a heat sensing wire whose mechanical strength is smaller than the terminal is connected in the middle of the terminal, the insulating board is connected in parallel.
It has sufficient mechanical strength, allows the capacitor element to be placed in a predetermined position within the mold, prevents uneven thickness of the exterior, and allows the exterior of the resin mold to be accurately provided.

In addition, in the above embodiment, the heat sensing wire is connected to both ends of the capacitor element, but it may be connected to either end of the capacitor element.

As described above, according to the present invention, abnormal heat generation of the capacitor element can be detected in all parts of the electric wire, so compared to the conventional temperature fuse where the sensing part is localized, it operates more reliably and can be detected from the external circuit. It is possible to cut off the current and prevent destruction and combustion of the capacitor element and exterior, and since the disconnected part of the heat sensing wire is completely insulated, a resin-clad capacitor can be obtained that can prevent malfunction without becoming conductive again. .

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of an embodiment of the present invention, Fig. 2 is a plan view of an insulated substrate and a heat sensing wire connected to a terminal used in an embodiment of the present invention, and Fig. 3 is an embodiment of the present invention. Fig. 2 shows a front sectional view of the heat sensing wire used in the operation after operation. 1...Capacitor element, 3a, 3b...Terminal,
4...Exterior, 5a, 5b...Insulating substrate, 7a, 7
b... Heat sensing wire, 8... Electric wire, 9... Plastic insulator, 10... Capacitor.

Claims (1)

[Claims for Utility Model Registration] (1) In a resin-clad capacitor in which a capacitor element is provided with a resin exterior, a terminal connected to the capacitor element and drawn out from the exterior, and a terminal connected in the middle of the terminal to insulate the terminal. A resin-clad capacitor comprising a separable insulating substrate and a heat-sensing wire connected to the separated portion of the terminal. (2) Utility model registration claim 1, in which the heat-sensing electric wire comprises an electric wire made of a low-melting point metal and a flame-retardant plastic insulator that melts around the melting point of the electric wire coated on the electric wire Resin-clad capacitor.