JP2932234B2 - Drip-proof self-cooling type wound resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drip-proof self-cooled wound resistor, and more particularly to a drip-proof self-cooled wound resistor mounted on an electric vehicle.

[0002]

2. Description of the Related Art Winding resistors for electric power mounted on electric vehicles are required to have good heat radiation and hermeticity against wind and rain. For this reason, the conventional wire wound resistor for electric power has a configuration in which a resistor is sealed with resin in a heat dissipation container provided with a large number of heat dissipation pieces on the outer surface. Such a power winding resistor is disclosed in, for example, Japanese Utility Model Laid-Open No. 58-11201.

[0003]

The heat radiating container in the conventional wire wound resistor for electric power has joints and joints formed by components, and these components are integrated by soldering or caulking. In addition, there is a problem in the airtightness and the production is troublesome. In addition, since the heat radiating container is in use for a long period of time exposed to wind and rain, it is corroded by the accumulation of dust and the capillary phenomenon that accumulates at the joints and seams of the components, and the sealing performance is reduced. The characteristics will be degraded. An object of the present invention is to provide a drip-proof self-cooling type wire wound resistor which has excellent drip-proof properties and can be easily manufactured.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide a heat dissipating container having a plurality of heat dissipating pieces on its outer peripheral surface.
To assemble a resistor that is used to fix the heat radiating container during assembly and that is integrally formed with a mounting seat to be attached to the mounting part and an edge part that fits and guides the lid on the opening side, and fixes the heat radiating container. Is achieved by

[0005]

[Function] Since the opening edge of the heat radiation container having a large number of heat radiation pieces and the mounting seat at the bottom are integrally formed, it is excellent in drip-proof property, and it is possible to assemble the resistor by fixing the heat radiation container. Because it can be made, it is easy to manufacture.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal section of a winding resistor according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1 in a state where no cross section is provided, and FIG. The plan view and FIG.
FIG. 3 is a half sectional view as viewed from AOA in FIG. 2. 1 to 4
The porcelain tube 1 is made of ceramics, ceramics, or the like and fired in a substantially cylindrical shape, and has a groove portion 1a and a flat portion 1b on its end surface. As shown in FIG. 6, a resistance wire (a nichrome wire or a manganin wire) 3 is wound around the outer peripheral surface of the insulator tube 1. Terminal fittings 2-1 and 2-2
As shown in FIG. 5, at the lower end, a guide claw 2a for mounting in the groove 1a of the insulator tube 1, a fixing claw 2b for fixing to the flat portion 1b of the insulator tube 1, and a buffer claw for receiving the tension of the resistance wire 3 2 c and a connection claw 2 d for connecting the resistance wire 3. The terminal fitting 2-1 is electrically connected to one end (upper end) of the resistance wire 3, and the terminal fitting 2-2 is electrically connected to the other end (lower end) of the resistance wire 3. As shown in FIG. 5, the terminal fitting 2-2 is provided with a semicircular bent portion 2f at two places and a hole 2g. The terminal fittings 2-1 and 2-2 are formed by stamping and molding a conductive metal plate such as copper or phosphor bronze with a press or the like. The combination of the insulator tube 1, the terminal fittings 2-1 and 2-2, and the resistance wire 3 is referred to as an assembly resistor 4.
The heat radiation container 5 has a large number of heat radiation pieces 5b protruding radially on the outer peripheral surface of the cylindrical portion 5a. A mounting portion (mounting seat) 5g is formed outside the bottom 5c of the cylindrical portion 5a, and a screw hole 5k is formed in the mounting portion 5g. Also, the bottom 5
A thin portion 5f is formed substantially at the center of c. On the other hand, an edge portion 5d having a larger diameter than the cylindrical portion 5a is provided at the opening of the heat radiation container 5.
And a thick portion 5e for holding a screw 12 described later. The heat dissipation container 5 is integrally formed by aluminum die casting from the viewpoint of mechanical strength and heat resistance. An insulating cylinder 7 having good heat resistance is provided at a step portion on the inner peripheral surface between the cylindrical portion 5a and the edge portion 5d of the heat radiation container 5. The cylindrical portion 5a
An insulating plate 8 made of an extremely thin polyimide film is closely arranged on the inner peripheral surface of the substrate. The insulating plate 8 is also in close contact with the lower part of the insulating cylinder 7. An insulating container 9 is arranged in contact with the bottom 5c of the heat radiating container 5. A step is provided inside the insulating container 9 to control the positioning and movement of the insulator tube 1 during assembly. The lid 6 seals the opening of the heat radiation container 5 and is made of an insulating material such as plastic mixed with glass fiber. The lid 6 has a circular temperature indicator coating portion 6d slightly protruding at a substantially central portion of the flat portion 6a, and has a cylindrical shape 2 protruding upward on both sides of the coating portion 6d.
The terminal support portions 6c are provided. Further, a porcelain tube support 6b projecting downward to support the porcelain tube 1 is provided below the flat portion 6a. The temperature indicator 14 is applied in a circular shape to the application section 6d. Temperature indicator 14
Is such that, for example, it is blue at normal temperature, becomes red at functional temperature, and does not return to its original color even if the temperature subsequently decreases. A packing 11 is provided between the heat radiating container 5 and the lid 6, and an edge portion 5 of the heat radiating container 5 is provided.
d and the flat portion 6a of the lid 6 fitted to the open surface of the edge portion 5d.
Is held between. The lid 6 is fastened at four places by screws 12 and fixed to the heat dissipation container 5. Screw 1
No. 2 is also used when the whole wire wound resistor according to the present invention is mounted on a housing. An O-ring 15 is provided in close contact with the inner peripheral surface of the edge 5d of the heat dissipation container 5. Cement 10 is sealed between the assembled resistor 4 and the insulating plate 8 in the heat dissipation container 5 and in the hollow of the insulator tube 1. The cement 10 is obtained by pulverizing an inorganic agent such as silica (quartz) into a particle range of about 0.005 to 1.0 mm, adding a very small amount of monomethyl silicone resin powder, mixing in a dry state, and heating. Then, the methyl group of the silicon resin is separated and diffused as carbon dioxide gas and water, and the remaining component (silica) connects the fine powder of silica and solidifies. The addition of a small amount of monomethyl silicon resin powder is for improving heat conduction. In the wound resistor configured as above, one of the porcelain tubes 1 is incorporated into the heat radiating container 5 via the insulating container 9, and the other is similarly combined with the heat radiating container 5 via the supporting portion 6 b of the lid 6. It is. The assembly resistor 4 is restricted from moving in the circumferential direction and the center direction, and can be accurately held without eccentricity. Therefore, variations in characteristics such as insulation resistance, insulation withstand voltage, and heat radiation can be reduced.

Next, the assembly of the wound resistor will be described. First, the assembled resistor 4 is created. First, the guide claws 2a of the terminal fittings 2-1 are attached to the groove 1a of the insulator tube 1 while being brought into contact with the inner diameter side of the insulator tube 1, and fixed as if the flat claws 2b sandwich the fixed claws 2b with the flat portions 1b. Similarly, while the guide claw 2a of the terminal 2-2 is in contact with the other inner diameter side of the porcelain tube 1, it is mounted in the groove 1a such that the bent portion 2f is inside the porcelain tube 1, and the fixed claw is fixed by the flat portion 1b. 2b and fix it. Next, as shown in FIG. 7, the upper end of one end of the resistance wire 3 is wound around the connection claw 2d of the terminal fitting 2-1 and then the outer peripheral surface of the insulator tube 1 is wound via the buffer claw 2c. When it reaches the terminal fitting 2-2, it is wound around the connection claw 2d via the buffer claw 2c. Then, the resistance wire 3 and the connection claw 2d are formed by silver brazing, spot welding, or the like.
Make the space stable and fixed, and connect them electrically. In this way, the tension when the resistance wire 3 is wound around the outer peripheral surface of the insulator tube 1 is stopped by the buffer claw 2c, and the connection claw 2c
Since the resistance wire 3 does not act on a portion where the strength is reduced due to heat at the time of silver brazing or spot welding of the resistance wire 3 at d, troubles such as disconnection can be prevented even after long use. Note that the resistance wire 3 can be folded back by the terminal fitting 2-2 and returned to the terminal fitting 2-1 to be wound a plurality of times, and the resistance wire 3 can be wound not on the connection claw 2d but on the fixed claw 2b. Electrical connection can also be made. On the other hand, the insulating cylinder 7 is attached to the heat radiating container 5 and the insulating plate 8 is closely arranged, and then the insulating container 9 is installed at the bottom. The heat radiation container 5 is set upright as shown in FIG. 1, and a bolt is screwed into the hole 5k and fixed.
The assembled resistor 4 assembled as shown in FIG. 6 is inserted into the heat radiating vessel 5 in this state, the position is adjusted using a jig (not shown), and the arrangement is made as shown in FIG. And cement 10
After vibrating, the jig is removed and heated at 200 ° C. for about 3 hours to fix the cement 10. The solidification of the cement 10 fixes the components. Thereafter, the lid 6 is fastened and fixed to the heat radiating container 5 with the screws 12 via the packing 11, and a sealing agent or an adhesive is injected and solidified into the gap between the terminal fitting 2 and the terminal supporting portion 6 c of the lid 6. Then, the inside is sealed and the assembly is completed.

The winding resistor according to one embodiment of the present invention is configured as described above, and is provided with a semicircular bent portion 2f in the terminal fitting 2-2. Terminal fittings 2-1 and 2-2
When a voltage is applied during this period, the resistance wire 3 generates heat. The heat generated by the resistance wire 3 is diffused and transmitted to each part of the heat radiation container 5 via the cement 10, and the temperature rises as a whole. When the voltage is cut off, the heating of the resistance wire 3 is stopped, and the entire temperature drops. If this voltage application and interruption are repeated, thermal stress due to the difference in the thermal expansion coefficient of the material between the components may act, which may lead to breakage of the terminal fitting 2-2. According to the verification test by the overload performed by the present inventors, the terminal fitting 2-2 penetrating the cement 10 inside the insulator tube 1 was totally shrunk and broken. As in the above-described embodiment, the semicircular bent portion 2f provided on the terminal fitting 2-2 deforms and absorbs substantially linearly when subjected to thermal stress, thereby preventing breakage due to shrinkage. Note that the shape, number, arrangement, and the like of the distorted portions 2f can be changed as appropriate. As shown in FIG.
The hole 2g is provided as shown in FIG. When an overcurrent flows, the terminal fitting 2-2 is broken at the hole 2g so as to play a protective function. On the other hand, by observing the color of the temperature indicator 14 applied to the molded portion 6d of the lid 6, it is determined whether the temperature indicator 14 has been used at or above the use limit temperature at the time of a periodic inspection or the like. I can do it. Further, a thin portion 5f is formed at the bottom 5c of the heat radiating container 5. When an overvoltage is applied to the resistance wire 3 for some reason, the amount of heat generation increases, and the internal pressure of the resistor excessively increases, the thin portion 5f is formed. 5f is destroyed to lower the internal pressure and prevent a disaster due to the rupture of the entire resistor. The thin portion 5f of the heat radiating container 5 is naturally installed in a safe place even if the portion is broken. In addition, since the cement 10 to be filled and solidified outside the resistance wire 3 uses a dry powder without solvent, the work of filling, heating and solidifying can be completed in one operation, and the heat conductivity is good, so that the heat dissipation is good. In combination with the heat radiation effect of the heat radiation piece portion 5b of the container 5, there is an effect of suppressing a temperature rise of the resistance wire 3. Furthermore, since the cement 10 has a high insulation resistance, the insulation resistance 8 and the insulation withstand voltage characteristics can be improved together with the insulating plate 8 wound around the inner peripheral surface of the heat dissipation container 5. Further, as shown in FIG. 4, a projection 5h is provided on a part of the heat radiation piece 5b, and a part of the heat radiation piece 5b is formed in a tapered shape 5i. Thereby, the mechanical strength of the heat radiation piece 5b is improved and the surface area is increased, so that the heat radiation effect can be further improved.

Next, FIG. 8 shows another example for preventing breakage of the terminal fitting 2-2 due to heat shrinkage. FIG.
FIG. 3 is an enlarged view of a main part of another example of the terminal fitting. The surface of the terminal fitting 2-2 is covered with a thin wire, for example, a flat braided copper wire 2m by JCS (Japan Cable Industry Association Standard) 236B. The direct contact area between the cement 10 and the cement 10 is reduced, and the flexibility of the flat braided copper wire 2m absorbs the dimensional change due to the thermal stress between the cement 10 and the terminal fitting 2-2. Instead of the flat braided copper wire, an aluminum foil used at home may be wound, or a paint, for example, fine powder of alumina silicate may be dispersed in an alcohol solution, applied, and dried.

FIG. 9 shows a state in which three winding resistors are mounted on the gantry 13. When the screw 12 is inserted into the gantry 13 and the gantry 13 is fastened and fixed to the thick portion 5e, the mounting surface side of the edge 5d of the heat radiation container 5, the lid 6, and the exposed portion of the terminal 2 are shielded from the outside air. Will be done. In such a state, the place exposed to the outside air, that is, the wind and rain,
The outer surface of the cylindrical portion 5a, the heat radiation piece portion 5b, the outer surface of the bottom portion 5c, the auxiliary mounting portion 5g, and the like. However, since there are no joints or joints between components in any part,
Almost no dust adhesion and moisture retention due to wind and rain. Therefore, the surface corrosion of the heat radiating container 5 is minimized, and the sealing performance does not decrease for a long period of time.

[0011]

According to the present invention, since the opening edge and the mounting seat at the bottom of the heat radiating container having a large number of heat radiating pieces are integrally formed, a wound resistor excellent in drip proofness can be obtained. And
Since the resistor is assembled by fixing the heat dissipation container, the production can be simplified.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a wire-wound resistor according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG. 1 without a cross section.

FIG. 3 is a plan view of FIG. 1 in a state where a lid is removed without a cross section.

FIG. 4 is a half sectional view taken along line AOA of FIG. 2;

FIG. 5 is an enlarged view of a main part of a terminal fitting.

FIG. 6 is an external view of an assembled resistor.

FIG. 7 is a view showing a mounting state of a terminal fitting.

FIG. 8 is an enlarged view of a main part showing another example of the terminal fitting.

FIG. 9 is a diagram showing a state in which a winding resistor is attached to a gantry.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulator tube 2 Terminal fitting 3 Resistance wire 5 Heat radiating container 5b Heat radiating piece 5d Edge 5g Mounting part 6 Lid 7 Insulating cylinder 8 Insulating plate 9 Insulating container 10 Cement

──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsumi Watanabe, Inventor 1070 Ma, Katsuta-shi, Ibaraki Pref., Ltd., Mito Plant Co., Ltd. Inside the Mito Plant (56) References Japanese Utility Model Opening No. 59-91701 (JP, U) Japanese Utility Model Open No. 58-11201 (JP, U) Japanese Utility Model Opening 3-128902 (JP, U) Japanese Utility Model Opening No. 57-134801 (JP, U.S.A.) U) (58) Field surveyed (Int.Cl. ⁶ , DB name) H01C 1/02 G01K 3/02 H01C 1/024 H01C 1/144 H01C 3/20

Claims (6)

(57) [Claims] 1. A heat-dissipating container which has a substantially cylindrical shape with a bottom, has a large number of heat-dissipating pieces on the outer peripheral surface, has an edge on the opening side and a mounting seat protruding outward on the bottom, and is integrally formed. And two terminal fittings that are locked to the insulator tube around which the resistance wire is wound and are drawn out from both ends of the resistance wire. A drip-proof self-cooling type winding comprising a cement made of a particulate inorganic material which is filled and solidified when heated, and a lid for closing an opening of the heat dissipation container and fixing and supporting the two terminal fittings. Wire resistor. 2. A heat-dissipating container which has a substantially cylindrical shape with a bottom, has a large number of heat-dissipating pieces on the outer peripheral surface, has an edge on the opening side and a mounting seat protruding outward on the bottom, and is integrally formed. And two external metal fittings provided with a heat shrinkage absorbing portion, which are locked to the insulator tube around which the resistance wire is wound and are drawn out from both ends of the resistance wire, and are sealed in the heat dissipation container. An assembling resistor, a cement made of a particulate inorganic material filled in the heat dissipation container and solidified when heated, and a lid for sealing an opening of the heat dissipation container and fixing and supporting the two terminal fittings. Drip-proof self-cooling type wound resistor equipped with a body. 3. The drip-proof self-cooling type wire wound resistor according to claim 2, wherein the heat shrinkage absorbing portion is a distorted portion obtained by distorting the terminal fitting. 4. A heat-dissipating container which has a substantially cylindrical shape with a bottom, has a large number of heat-dissipating pieces on its outer peripheral surface, has an edge on the opening side and a mounting seat protruding outward on the bottom, and is integrally formed. And an assembling resistor enclosed in the heat radiating container, comprising: two terminal fittings drawn out from both ends of a resistance wire wound around an insulator tube formed into a substantially cylindrical shape by an insulator; An insulating plate closely attached to the inner peripheral surface of the insulating container, and an insulating container disposed at the bottom of the heat radiating container to restrict movement of the assembled resistor;
An insulating cylinder provided at a step portion at an edge of the heat dissipation container, a cement made of a particulate inorganic material which is filled in the heat dissipation container and solidifies when heated, and hermetically seals an opening of the heat dissipation container. A drip-proof self-cooling type wire wound resistor comprising a lid for fixing and instructing two terminal fittings. 5. A heat-radiating container integrally formed, having a substantially cylindrical shape with a bottom, a large number of heat-radiating pieces on an outer peripheral surface, an edge portion on an opening side, and a mounting seat protruding outward on a bottom portion. And two terminal fittings that are locked to the insulator tube around which the resistance wire is wound and are drawn out from both ends of the resistance wire. A drip-proof self-cooling type winding that includes a cement made of a particulate inorganic material that is filled and solidified when heated, and a lid that seals an opening of the heat radiation container and has a temperature indicator application portion formed thereon. Wire resistor. 6. A substantially cylindrical shape with a bottom, a plurality of tapered heat dissipation pieces on an outer peripheral surface, an edge portion on an opening side, and a mounting seat projecting outward on a bottom portion, and are integrally formed. An assembling resistor enclosed in the heat dissipation container, the heat dissipation container having two terminal fittings drawn out from both ends of a resistance wire wound around an insulator tube formed into a substantially cylindrical shape by an insulator; A protection comprising a cement made of a particulate inorganic material which is filled in the heat dissipation container and solidifies when heated, and a lid which seals an opening of the heat dissipation container and has a temperature indicator application portion formed thereon. Drop self-cooling type wound resistor.