JPS61110401A - Covered winding resistor for power - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a coated wire-wound resistor for power use used in various control systems such as railway vehicles and elevators, and particularly to a coated wire-wound resistor using silicone resin as the coating material. This invention relates to a coated wire-wound resistor for electric power using.

[Background of the invention]

Various types of resistors are known for use in electrical circuits, but in control systems for railway vehicles and elevators, coated wire-wound resistors for power use as shown in Figures 2 and 3 are used. utensils are mainly used.

In these figures 2 and 3, l is a winding core made of ceramic material, 2 is a terminal, 3 is a resistance wire such as nichrome wire, 4
After the resistance wire 3 is wound around the winding core 1 using an insulating coating such as enamel, an insulating liquid N4 is applied to protect the whole electrically and mechanically. Note that the cross-sectional shape of the winding core 1 is not limited to the cylindrical shape shown in the figure, but may also be cylindrical, elliptical, rectangular, or the like.

By the way, such a power wave rR wire-wound resistor (hereinafter referred to as
As mentioned above, the mainstream of automobile resistors has traditionally been those using enamel as the insulating coating 4. According to resistors coated with this enamel, the insulation coating has good adhesion to the ceramic material and resistance wire that form the core of the resistor, and high strength is obtained, making it robust and durable for long-term use. Although it has advantages,
On the other hand, the powdered enamel glaze, which is the raw material for enamel coating, contains lead, which is a major component of pollution problems, so its use is being discouraged, and alternatives to it are being discouraged. Resistors coated with silicone resin paint have started to attract attention.

However, such silicone resin-based paints have inferior viscosity and adhesion after coating formation compared to enamel, and are therefore not compatible with resistor cores and resistance wires, resulting in many cracks in the coating. This is unavoidable, and in the worst case, part of the coating may fall off, making it difficult to maintain sufficient reliability with conventional resistors coated with silicone resin. There was a drawback.

[Purpose of the invention]

An object of the present invention is to provide a resistor coated with a silicone resin, which eliminates the drawbacks of the prior art described above, has no risk of cracking, peeling, or falling off of the coating, and can obtain sufficiently high reliability. It is in.

[Summary of the invention]

In order to achieve this objective, the present invention mixes short fiber-like pieces made of an insulating material such as glass into the silicone resin that is to form the insulating coating of the resistor, thereby reinforcing the silicone resin coating. However, it is characterized by preventing the silicone resin coating from peeling, cracking, or falling off as a result.

[Embodiments of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the coated wound "4FA" resistor for power use according to the present invention will be explained in detail with reference to the illustrated embodiments.

1 and 4 show an embodiment of the present invention, in which a winding core l, a terminal 2. Resistance line 3. The silicone resin insulation coating 4 is the same as the conventional example explained in FIGS. 2 and 3, but short fiber-like pieces 5 are mixed in the silicone resin insulation coating 4 at a predetermined ratio. This embodiment has a different configuration from the above-mentioned conventional example.

The short fiber-like pieces 5 are made by crushing glass fibers with a thickness of 0.05 to 0.5 mm into lengths of about 1.0 to 10.0 mm, which are placed in silicone resin by weight. Approximately 30% of the insulating film ff4 is mixed in to form the insulation coating ff4.

At this time, the short fibrous pieces 5 may be mixed in a predetermined ratio in a dried silicone resin paint, and then cured after being applied to the resistor. Apply only the resin to a predetermined thickness on the resistor, and before it hardens, short fiber-like pieces 5 are sprinkled so that a predetermined amount adheres to the silicone resin coating and is mixed therein, After that, curing may be performed.

In this way, the silicone resin insulation coating 4 that has been cured with a predetermined amount of short fiber-like pieces 5 mixed therein becomes a crosslinked state due to the action of these short fiber-like pieces 5, deepening the physical bond, and tensile strength. The strength against breakage and breakage is significantly increased.

Therefore, according to this embodiment, the strength of the insulating coating 4 is sufficient to withstand stress caused by temperature rise of the resistor during energization, changes in ambient temperature, etc.
The crack resistance is improved, and it is possible to sufficiently prevent cracking, peeling, and falling off.

In addition, as a result of obtaining sufficient strength of the insulating coating 4 in this way, the impact resistance is also improved, and there is less risk of damage even if an object hits the surface of the resistor.
It also becomes easier to handle.

In addition, in the above embodiment, the silicone resin insulation covering fW4
Although the proportion of the short fibrous pieces 5 to be mixed in was set to 30% by weight, the present invention is not limited to this.

Furthermore, the material of the short fiber-like strips 5 is not limited to glass, but may be of any material as long as it has excellent heat resistance and strength, and is compatible with silicone resin, such as polyimide resin fibers. may also be used.

[Effects of the Invention] As explained above, according to the present invention, the cracking resistance of the resistor coating can be dramatically improved with a simple structure in which short fiber-like pieces are mixed into the insulation coating of the soric resin. Because it can increase the durability, it easily prevents the coating from tearing, peeling, or even falling off during use, ensuring a low-cost, high-reliability power Y1 wire-wound resistor. can be provided to

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of a power wave i-wound resistor according to the present invention, FIG. 2 is a side view showing a conventional example of a power sheathed wire-wound resistor, and FIG. Front view of the conventional example, No. 4
The figure is a front view of the embodiment of FIG. 1. 1... Winding core, 2... Terminal, 3... Resistance wire, 4...
・Silicone resin insulation coating, 5...Short fibrous pieces. Agent: Patent Attorney 2 Junji Department (and 1 other person) Figure 1 Figure 4

Claims (1)

[Scope of Claims] 1. A coated wire-wound resistor for power use coated with silicone resin, characterized in that the cover is composed of a mixture of short fibrous pieces of silicone resin and an insulating material. wire wound resistor. 2. A covered wire-wound resistor for power use according to claim 1, wherein the short fibrous strips are glass fiber strips.