JPH05234701A - Wire-wound resistor - Google Patents

Abstract

PURPOSE:To suppress the variation of resistance for higher reliability which may be caused by the aging of the contact between a cap and a resistance wire due to thermal stress in long time use in a temperature varying environment by attaching a cap with a projection to both ends of a porcelain and connecting the resistance wire to the projection to shorten the contact area between the cap and the resistance wire. CONSTITUTION:Connection between a resistance wire and a cap was conventionally provided at a deep point from the cut end of the cap. This lengthened the contact area between the cap and the resistance wire. Therefore, when the resistor was used for a long time in a temperature varying environment, the condition of the contact between the cap and the resistance wire sometimes changed due to thermal stress from the initial value, resulting in the variation of resistance. To cope with this, a cap 2 with a projection is used and a resistance wire 3 is connected to the projection. This suppresses the variation of resistance to improve the electrical characteristics for higher reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a wire wound resistor which requires high reliability in industrial equipment, automobile-related equipment, space-related equipment and the like.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become more sophisticated and electronically controlled, the demand for highly reliable wire wound resistors has increased remarkably as the demand for higher reliability has increased. A conventional technique is shown in FIG. In many cases, the cap and resistance wire are connected to each other at a location that is deep from the cut end of the cap, and when used for a long period of time in an environment with temperature changes, the contact state between the cap and resistance wire will be the initial state due to thermal stress. Because of the difference, the resistance value often changed.

[0003]

When manufacturing using such a conventional cap structure, the state of the cap and the resistance wire will change when used for a long period of time in an environment with temperature change. Since a winding resistor having high reliability against thermal stress is supplied, a method such as screening is generally used in many cases, which has been a factor of increasing the manufacturing cost. The present invention solves these problems and provides a winding resistor having high reliability against temperature changes.

[0004]

[Means for Solving the Problem] In order to solve this problem,
In the present invention, caps with convex portions are attached to both ends of the porcelain, the resistance wire is connected to the convex portion and wound in a spiral shape, and the resistance wire is connected to the convex portion of the other cap to form a resistor.

[0005]

EXAMPLE A first example of a wire wound resistor is shown in FIGS. In order to connect the resistance wire to the base body made of an insulator such as ceramic, caps with convex portions are attached to both sides of the porcelain. Mount the two protrusions so that they are in the same position. The winding pitch and the number of windings for each type of resistance wire were stored in a computer in advance so that the winding end position came to the convex portion of the opposite side cap, and a winding resistor having a desired resistance value was manufactured. Table 1 shows the reliability test results of the wound resistors manufactured by this manufacturing method. A second embodiment of the wire wound resistor is shown in FIG. In FIG. 3, a cap provided with a convex portion at one position on the winding start side and a plurality of caps on the winding end side is attached to a base body made of an insulator such as ceramic, and a resistance wire is connected. In this method, since the resistance wire is connected to one of the convex portions having a plurality of winding ends, it is possible to easily manufacture the wire wound resistor having a desired resistance value as compared with the first embodiment.

[Brief description of drawings]

1 is a perspective view showing an embodiment of a wire wound resistor of the present invention. FIG. 2 is an explanatory view showing an example of connection between a resistance wire and a cap according to the first embodiment. FIG. 3 is a view of a resistance wire and a cap according to the second embodiment. Explanatory drawing showing connection example FIG. 4 is a perspective view showing an example of connection between a resistance wire and a cap according to the prior art 1: Base 2: Cap with protrusion for connecting resistance wire
3: Resistance wire 4: Non-flammable paint 5: Terminal wire 6: Conventional cap

Claims (2)

[Claims] According to the present invention, it is possible to stabilize the connection between the cap and the resistance wire by attaching a cap provided with a projection on both ends of the porcelain and connecting a resistance wire to the projection, and an environment with a temperature change. A method of manufacturing a wire wound resistor characterized by high reliability in which the resistance value is extremely small under the following conditions. 2. The winding resistor according to claim 1, wherein the cap is provided with a plurality of protrusions at a plurality of positions.