JP3414179B2 - Winding type noise prevention resistance wire - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire-type noise prevention resistance wire (hereinafter simply referred to as "wire") used for an ignition system of an automobile engine. 2. Description of the Related Art A wire core of this type is formed by extrusion-coating a fluoro rubber compound obtained by mixing a magnetic substance into a fluoro rubber on a center reinforcing core formed by twisting aramid fibers. In addition, by winding a resistance wire in a coil, the inductance value per unit length of the electric wire is increased to obtain a noise prevention effect. Further, the coil winding of the resistance wire is performed in a state in which the fluoro rubber compound in the outer layer portion of the core is not vulcanized, and the coil is wound while the resistance wire is embedded in the outer peripheral surface of the core. . The winding core (coil winding core) around which the resistance wire is coiled around the outer periphery is coated with an insulating layer and vulcanized with a fluororubber compound. [0003] By performing the coil winding of the resistance wire as described above in a state in which the fluorine rubber compound in the outer layer portion of the core is not vulcanized, the resistance wire does not sink into the outer peripheral surface of the core and does not shift sideways. The coil is wound at a uniform pitch. Also, when removing the insulating layer at the end of the electric wire and bending the exposed coil core onto the insulating layer and connecting the terminal fitting to the electric wire, the resistance wire is not loosened from the core. Thus, the terminal fitting can be securely connected. A conventional fluorine rubber used for manufacturing such a core of an electric wire has a Mooney viscosity of 40 ML _{1 + 4} (10
(0 ° C.), and a ferrite powder or the like, which is a magnetic substance, is mixed into the fluororubber to form a fluororubber compound. However, a core using a fluororubber compound formed of a fluororubber having a Mooney viscosity of 40 ML _{1 + 4} (100 ° C.) has a problem that the outer layer portion of the fluororubber compound is not used. There is a problem that the resistance wire is too soft, and the resistance wire is excessively entangled in the core when the resistance wire is wound into a coil. If the resistance wire to the winding core is excessively sinking, resistance wire buried in the interior of the winding core, resulting inconvenience to say resistance becomes unstable between the terminal fitting to be connected to the wires and the resistance wire. [0006] If the fluororubber compound is too soft, there is a problem that the core is deformed when the formed core is wound on a bobbin. The deformation of the core occurs because the cores wound on the bobbin are pressed against each other with a strong pressure, and the degree of the deformation increases as the lower part of the core is wound. When the core is deformed, variations occur in the coil winding pitch of the resistance wire and the depth of the resistance wire embedded in the outer periphery of the core in the coil winding step.
If the coil winding pitch of the resistance wire is disturbed, contact of the resistance wires between the turns of the coiled adjacent resistance wire occurs, so that a predetermined inductance value cannot be obtained and noise of the electric wire is prevented. Performance decreases. [0007] In view of the above problems, the present invention has an appropriate hardness in the unvulcanized state of the fluororubber compound in the outer layer portion of the core, so that the resistance wire is excessively dipped into the core, and It is an object of the present invention to provide a wire-wound noise-prevention resistance wire that can prevent deformation of a winding core when the winding core is wound around a bobbin. [0008] The technical means for achieving the above object is to provide a fluoro rubber compound containing fluoro rubber and a magnetic substance mixed in the fluoro rubber on a central reinforcing core. A core formed by extrusion coating molding in an unvulcanized state, a resistance wire that is coil-wound while being embedded on the outer peripheral surface of the core on the core, and the core from outside the resistance wire. An insulating layer for coating, wherein the fluororubber compound is vulcanized after the coiling of the resistance wire is completed, and wherein the fluororubber has a temperature of 100 ° C.
And Mooney viscosity of 40 fluororubber Kino, temperature 100
4 to 6 with fluoro rubber having Mooney viscosity of 65 at ℃
Characterized by being mixed at a weight ratio in the range of from 6 to 4. FIG. 1 is a perspective view of an electric wire (winding type noise prevention resistance electric wire) according to an embodiment of the present invention. This electric wire has a core 3 composed of a central reinforcing core 1 formed by twisting three 1000 denier aramid fibers and a fluororubber compound 2 covering the outer periphery of the central reinforcing core 1, and an outer periphery of the core 3. Wire 4 spirally wound around the coil, an insulating layer 5 covering the outer periphery of the winding core 3 from outside the resistive wire 4, a glass braid 6 covering the outer periphery of the insulating layer 5, and a further outer periphery of the glass braid 6. The outer circumference of a coil core 8 formed by coiling the resistance wire 4 around the core 3, that is, between the coil core 4 and the insulating layer 5, is provided with a silicone oil. Is applied. The winding core 3 is formed by extrusion-molding an unvulcanized fluoro rubber compound 2 by a predetermined extruder on a center reinforcing core 1 continuously fed from a supply reel. The formed core 3 is once wound around a bobbin before the step of coiling the resistance wire 4. The fluororubber compound 2 used to form the core 3 has a first fluororubber having a Mooney viscosity of 40 ML _{1 + 4} (100 ° C.) and a second fluororubber having a Mooney viscosity of 65 ML _{1 + 4} (100 ° C.). of a fluorine rubber, a resilient material 100 parts by weight were mixed in a weight ratio ranging from 6: 4 to 4: 6, and full Erai <br/> preparative powder 400 parts by weight Ru magnetic der, processing aids 1 Parts by weight, and 6 parts by weight of a vulcanizing agent, and a fluororubber compound 2 is formed by using an elastic material obtained by mixing the first fluororubber and the second fluororubber in the above weight ratio. By doing so, the fluororubber compound 2 having a predetermined Mooney viscosity value capable of preventing the resistance wire 4 from being excessively entangled and the core 3 from being deformed is obtained.
In addition, a specific mixing example of the first fluoro rubber and the second fluoro rubber will be described later. The resistance wire 4 has an outer diameter A of 35 to 80 μm.
And a coil wound around the core 3 at a pitch of 4000 to 12000 times per meter by a predetermined coil winding machine. The coil winding of the resistance wire 4 is performed in a state where the fluororubber compound 2 of the core 3 is not vulcanized. Therefore, the resistance wire 4 to be coiled is wound while being coiled into the outer peripheral surface of the core 3. It has become so. In addition, the fluorine rubber compound 2
Since the hardness in the unvulcanized state has become appropriate hardness,
As shown in FIG. 2, the resistance wire 4 wound by a coil is
Moderate depth B (1/4 to 1/2 of outer diameter A of resistance wire 4)
At a depth of about 3 mm). The insulating layer 5 is made of EP rubber, silicone or cross-linked PE (polyethylene).
It is made of P rubber or silicone. The electric wire thus configured has an outer diameter of 5 to 7 mm. As described above, according to the present embodiment, since the hardness of the outer layer portion of the core 3 in the unvulcanized state of the fluororubber compound is appropriate, the resistance wire 4 is wound around the core 3 by coil winding. In doing so, it is possible to prevent the resistance wire 4 from being excessively entangled in the core 3 and to prevent the core 3 from being deformed when the core 3 is wound around a bobbin. In the following, the first ratio will be described with some specific mixing ratios.
The results obtained by mixing the fluororubber with the second fluororubber and evaluating the resulting fluororubber compound 2 are shown. Here, as shown in Table 1, the case where the elastic material into which the ferrite powder or the like is mixed is formed of only the first fluoro rubber (A), the first fluoro rubber and the second fluoro rubber are used. (B, C, D, E) in the case of mixing with a weight ratio of 7: 3, 6: 4, 5: 5, 4: 6, and (F: ) Were measured and evaluated for the physical properties of the formed fluororubber compound. In any of the cases A to F, 400 parts by weight of ferrite powder, 1 part by weight of a processing aid, and 6 parts by weight of a vulcanizing agent were mixed in the upper part of the obtained elastic material 100. The numbers in Table 1 indicate the weight ratio of the first and second fluororubbers, ferrite powder, processing aid, and vulcanizing agent to be mixed. [Table 1] [Table 2] [Table 3] Table 2 shows the results of measurements of the Mooney viscosity, tensile strength and elongation of the fluororubber compounds A to F. Table 3 shows the extrudability of the fluororubber compounds A to F, It shows the results of evaluation of the degree of inset of the resistance wire 4 and the degree of deformation of the core 3 when the core 3 is wound around a bobbin, and the results of comprehensive evaluation of each fluororubber compound. From the results shown in Tables 2 and 3, the fluorine compounds of C, D, and E have appropriate hardness, are excellent in extrudability, can prevent the resistance wire 4 from being excessively entangled, and can be wound. This prevents deformation when the core 3 is wound around a bobbin. On the other hand, since the fluororubber compounds A and B are too soft, there is a problem that the resistance wire 4 is excessively entangled or deformed by being wound around a bobbin. There is a problem that the workability is poor and the resistance wire 4 is insufficiently sunk into the core 3. From this, it can be seen that the mixing ratio of the first fluoro rubber to the second fluoro rubber is appropriately in the range of 4: 6 to 6: 4. As described above, according to the present invention, the hardness of the outer layer portion of the core in the unvulcanized state of the fluororubber compound becomes appropriate and the resistance to the core is reduced. When the wire is coiled, the resistance wire can be prevented from being excessively entangled in the core, and the resistance between the terminal fitting connected to the electric wire and the resistance wire can be prevented from becoming unstable. At the same time, the core can be prevented from being deformed when the core is wound on a bobbin, and the noise prevention performance of the electric wire can be prevented from lowering.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a wire-type noise prevention resistance wire according to an embodiment of the present invention. FIG. 2 is a sectional view of a coil core of the wire-type noise prevention resistance wire of FIG. 1; [Description of Signs] 1 Center reinforcing core 2 Fluororubber compound 3 Core 4 Resistance wire 5 Insulating layer

Claims (1)

(57) [Claim 1] Extrusion coating molding of a fluororubber compound containing a fluororubber and a magnetic substance mixed in the fluororubber on a central reinforcing core in an unvulcanized state. A core formed, a resistance wire coil-wound while being embedded on an outer peripheral surface of the core on the core, and an insulating layer covering the core from outside the resistance wire; In a wire wound anti-noise resistance wire in which a rubber compound is vulcanized after the coil winding of the resistance wire is completed, the fluorine rubber has a Mooney viscosity of 40 at a temperature of 100 ° C. and a fluorine rubber of a temperature of 100 ° C. A wound-type noise-prevention resistance wire comprising a mixture of fluorine rubber having a Mooney viscosity of 65 at that time in a weight ratio of 4: 6 to 6: 4.