JPS5844563Y2 - wire wound resistor - Google Patents

Description

[Detailed description of the invention] This invention relates to a wire-wound resistor, which improves reliability by omitting terminals for circuit wiring and directly crimping the stranded conductor of the insulated wire to the resistance wire of the resistance element. The purpose is to obtain a wire-wound resistor that is high in cost, saves resources, and saves man-hours.

Recently, with the development of printed wiring technology, the number of wire-wound resistors for printed wiring boards is increasing. structures are widely used.

The electric wires are usually connected by a known method such as soldering, wire wrapping, or faston connector connection, and the wire-wound resistor is provided with terminals having shapes suitable for each connection method.

As such a wire-wound resistor, for example, U.S. Pat.
There are issues such as No. 19210.

FIG. 1 shows an example of a resistance element of a conventional wire-wound resistor.

A is a front view, and C is a side view showing a partially cutaway cross section, where A shows the first example and C shows the second example.

That is, the opening in Figure 1 is made by winding a resistance wire 3 around an insulating core 2, fitting terminal fittings 4 integrally equipped with metal terminals 5 at both ends, and applying pressure from the periphery. It has a structure that makes pressure contact with the resistance wire 3.

Although the terminal 5 is shown in the shape of a lug terminal for soldering in FIG. 1, it goes without saying that it may have any other shape suitable for each of the above-mentioned wire connection methods.

FIG. 1C shows the structure of a wire-wound resistor disclosed in JP-A-52-120362, in which a bent portion 5' formed integrally with the terminal 5 is sandwiched between the terminal fitting 4 and the resistance wire 2. The terminal fitting 4 is made of a material that is mechanically strong and has good deformability, and the terminal 5 is made of a material with good conductivity. FIG. 2 is a perspective view of six examples of conventional wire-wound resistors equipped with the above-mentioned resistance element 1, and shows the state in which wiring wires 9 and 10 are connected to the resistors and parts A and B, respectively. FIG.

The wire-wound resistor 6 has an insulating casing 7 filled with a covering layer 8 of an insulating material such as cement, and the resistance element 1 is buried within the covering layer 8 with the terminal 5 protruding from the covering layer 8. When this is used as a circuit element, it is connected to other components A and B by wiring 9 (length Ll) and wiring 10 (length L2).

In this case, the current path from the wiring 9 to the wiring 10 is formed by the pieces 9-5.4-3-4.5-10 in the case of the above-mentioned -th side port, and is formed by the pieces 9-5.4-3-4.5-10 in the case of the second example 9-5.5'-35,
5'-10, each with four connection points.

Having such a large number of connection points increases the number of man-hours during manufacturing, and has the disadvantage that there is a risk that the reliability of the product will decrease.

In addition, in the structure of the above-mentioned side opening, the terminal fitting 4 equipped with the terminal 5 is made of copper alloy such as brass because it is necessary to improve contact resistance and heat dissipation, but the mechanical gripping force is likely to be insufficient. There are drawbacks.

As a countermeasure for this problem, there are known methods such as (I) welding the resistance wire 3 to the terminal fitting 4 and (II) forming a soft film such as a tin-lead alloy on the terminal fitting 4, but both methods require a lot of man-hours. increases, and costs rise.

Further, in the structure of the second example C, it is necessary to provide a terminal 5 having a complicated bending portion 5' in addition to the terminal fitting 4, which increases the number of parts and the number of man-hours, leading to an increase in cost.

The present invention aims to improve the above-mentioned drawbacks, and examples will be explained below with reference to the drawings.

As shown in FIG. 3 (partially cut away), the winding element 11 of the present invention has a winding core 2 made of a glass fiber string with a diameter of approximately 3.2 mm, and a resistance wire such as a nichrome wire or a copper-nickel resistance wire. 3 is wound, and the conductor is a copper stranded wire (0,18
A terminal fitting 1 made of mild steel with the conductor 14 of an insulated wire (20 mm
The resistance wire 3 and the conductor 14 of the insulated wire are brought into close contact with each other by fitting the wires 5 and pressing and tightening them from six directions using a tool.

FIG. 4 is a perspective view of the wire-wound resistor 16 of the present invention.

That is, the resistance element 11 is housed in an insulating casing 7 so that the insulated wires 12 and 13 protrude, and the insulating casing 7 is filled with a coating layer such as cement.

Length L that the insulated wire 12.13 protrudes from the coating layer 8
3. L4 is formed to have a predetermined length suitable for circuit wiring.

FIG. 5 is a sectional view taken along line C--C in FIG. 3, and the arrow indicates the direction in which the pressure crimping tool presses.

The winding core 2 is made from a glass fiber string, the resistance wire 3 has a coil shape, and can be deformed, and since the conductor part 14 is a bare copper stranded wire, the tip can spread out into a fan shape. is possible.

Therefore, the core 2 and the resistance wire 3 are deformed by the crimping process, and the conductor 14 spreads along the inner periphery of the terminal fitting 15 as shown in the figure, and presses against each other while filling the inside of the terminal fitting 15. A good electrical connection between the wire and the insulated wire is formed.

FIG. 6 shows the terminal fitting 15 of the present invention, which has a thickness of approximately Q.
, made by drawing a 5mm mild steel plate into a cap shape.
A shows a cylindrical shape, a mouth and a deformed cylindrical shape with a convex part.

When used as an intermediate tap, use a bottomless cylinder.

2 shows an example 25 of the isometric metal fitting having a protrusion 25A for inserting the conductor part 14, and E is a cross-sectional view of the same, and E shows a cross section thereof, and the bottom part has a protrusion 25-1 to facilitate deformation of the bottom part. .

Figure 3 shows an example of a bottomless hollow terminal fitting, and Figure 2 shows a cross section of the second metal fitting after being pressed.

The terminal fitting 15 may be made of stainless steel or the like in addition to mild steel.

FIG. 7 is a partially cutaway view showing an example in which the present invention is applied to an intermediate tap of a resistance element, in which a copper stranded wire conductor 19 of an insulated wire 18 overlapped with a resistance wire 3 wound around a glass fiber string 2 is shown. The terminal fittings 17 are made of soft steel and have a deformed cylindrical shape, and are clamped together in a sandwich manner.

Since the present invention is constructed as described above, it improves the drawbacks of conventional products and has the following great industrial effects.

1. The electrical path from wiring 12 to 13 is 12-3-13
The number of parts is small, and the number of connection points is 2 compared to conventional products, which improves reliability and has a significant effect on reducing wiring man-hours and saving resources.

2. Since the insulated wires 12 and 13 can be formed in advance to a predetermined length required for mechanical assembly, the number of man-hours for mechanical assembly can be reduced.

3. The plastic deformation of a metal is related to its yield point, and the higher the yield point, the greater the hardness, but the value of the yield point (hardness) of the metal at the connection point of this invention shows some variation depending on the processing. but in the following order:

chrome wire)〉(copper nickel wire) = (hard steel)〉(copper wire) Therefore, the soft copper stranded wire that spreads along the inner wall of the hard terminal metal deforms plastically and contacts the resistance wire at multiple points and over a wide area. Therefore, without welding or special soft alloy treatment,
Forms a stable connection with low contact resistance.

4. The shape of the terminal fitting is simple, which allows for saving of man-hours and resources.

5. By making the terminal fitting into a deformed cylindrical shape with a convex portion on the peripheral wall, even if the conductor 14 is overlapped on the resistance wire, it can be easily fitted.

6. Since the terminal fitting does not act as a conductive path, materials with high Young's modulus and hardness can be selected, and crimping with strong gripping force can be performed.

7. Since the terminal fitting has a closed continuous cylindrical shape, the strength is high and the stress distribution is constant.

[Brief explanation of the drawing]

Figures 1 and 2 relate to a conventional wire-wound resistor. Figure 1 shows a wire-wound element, A is a front view, the opening is a partially cutaway side view, and C is a partially cutaway side view of another conventional example. Notched side view. FIG. 2 is a perspective view of a wire-wound resistor connected to parts A and B. Figures 3 to 7 relate to an embodiment of the wire-wound resistor of the present invention.
The figure is a partially cutaway side view of the resistance element, Figure 4 is a perspective view of the wire-wound resistor, Figure 6 shows the terminal fittings,
H2, E, H, and G are shape examples, and Figure 5 is Figure 3 C.
7 is a sectional view taken along the -C plane, and a partially cutaway side view showing a main part of an example of application to an intermediate tap. 1.11... Winding element, 2... Winding core,
3... Resistance wire, 4゜15... Terminal fitting, 5... Terminal, 7... Ceramic container, 8... Insulation coating Layer, 9, 10, 12, 13.
18...Insulated wire, 14.19...
·conductor.

Claims (1)

[Claims for Utility Model Registration] (1) At least one end or middle part of a resistance wire wound around a flexible core, the end of the conductor of an insulated electric wire whose conductor is made of stranded copper wire is The outer periphery of a resistance element is constructed by stacking the resistance wire on top of the resistance wire and pressing both the resistance wire and the wire conductor into contact with each other using a cylindrical terminal fitting with a closed peripheral wall made of a metal with a higher yield point strength than copper. of,
Wire-wound resistor (2) comprising an insulated coating except for the insulated wire; Wire-wound resistor (3) according to claim 1 of the utility model registration claim in which the flexible winding core is made of glass fiber string. The wire-wound type according to claim 1 or 2 of the utility model registration claim, in which the insulation coating around the resistive element is made of cement filled in a ceramic container, and the insulated wire connected to the resistive element is made to protrude outside the ceramic container. Resistor (4) The wire-wound resistor according to any one of claims 1 to 3 of the utility model registration claim, in which the terminal fitting is a cylinder or a cap-shaped cylinder (5) The terminal fitting is a cylinder or a cap-shaped cylinder. Registration of a utility model in which the wire-wound resistor (6) according to any one of claims 1 to 3 has a terminal fitting made of mild steel. A wire-wound resistor according to any one of claims 1 to 5.