JPH084651Y2 - Bundled wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a bundled electric wire, which is useful as wiring in a device, for example, a wire harness for an automobile.

(Prior Art) In recent years, the number of distribution lines in a device has been increasing due to the electronic and multifunctionalization of the device.

In the power distribution in the equipment, a large number of electric wires are pressed and bundled by a winding tape to make the wiring orderly, compact, and to prevent water infiltration or running water (running water passing through the wire gap).

(Problems to be solved) However, in the wire harness, the wires are not assembled by twisting them, but are assembled without twisting and are bundled by winding the presser-wrapping tape. Since it is not applied, the bending rigidity is high.In particular, the outer diameter of the bundle has increased recently due to the increase in the number of electric wires, and a large force is required for bending the electric wire bundle, and if the wire is forcibly bent, the electric wire may be damaged. This makes wiring work difficult.

In order to eliminate such a disadvantage, the wire bundle is tightened with a vinyl band or the like at regular intervals, or the winding of the press-winding tape is loosened. Destabilization and incomplete prevention of flooding cannot be avoided.

An object of the present invention is to provide a bundled electric wire which can stably bundle a large number of electric wires by winding a winding tape, ensure sufficient water resistance, and can be easily bent.

(Means for Solving the Problems) A bundled electric wire according to the present invention is a wire harness in which a large number of electric wires are pressed and wrapped with a winding tape to form a bundle, and an elastic body having a 50% compression load of 30 to 1000 g / cm ² This configuration is characterized in that an electric wire bundle (including an elastic material such as a plastic elastic body) is interposed in the electric wire bundle.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

 FIG. 1 is an explanatory view showing an embodiment of the present invention.

In FIG. 1, 1, ... are a large number of electric wires, and 2 is an elastic body interposed in the center of the electric wire group A, which is a continuous body over the entire length of the electric wire, and has a 50% compression rate of 30 to 1000 g / It is set to cm ² . Reference numeral 3 is a pressed tape wound around the outer circumference of the wire group by wrapping, and an adhesive vinyl tape can be used.

As the elastic body 2, a foamed plastic having a compression-restoring property can be used, and if the plastic has low water repellency, it is preferable to use a closed cell foam.

The above bundled electric wire is a large number of electric wires around the elastic body 1,
It can be manufactured by gathering the ... And winding the press winding tape 3 around the outer circumference. In this case, the elastic body 2 is compressed by the tightening force of the press-winding tape 3, and if the compressive stress δ of the elastic body 2 under tightening and the Young's modulus of the elastic body 2 are e, the outer diameter of the elastic body 2 is , (1-δ / e). Therefore, 50% compressive load of the elastic body 2 is 30g /
Since the elastic body 2 having a considerably high Young's modulus is used as cm ² or more, the outer diameter of the elastic body 2 in the compressed state, and hence the volume, can be sufficiently secured.

Since each wire of the wire harness is not twisted, a large stress (tensile stress, compressive stress) is generated with respect to tensile strain and compressive strain, and the Young's modulus is large.

When an ordinary wire harness without the elastic body 2 is bent, a large tensile stress acts on the bending tension side and a large compressive stress occurs on the bending compression side (the bending radius is R, the Young's modulus is Is E, the stress at the distance x from the bending neutral plane (center plane) is given by Ex / R, and if the radius of the wire harness is r, the maximum tensile stress on the bending tension side is + Er / R, The maximum compressive stress on the compression side is -Er / R). In this case, when an elastic body is interposed, the force that tries to compress the elastic body due to the tensile stress on the bending tension side and the compressive stress on the bending compression side (hereinafter referred to as a flattening force)
The greater the flattening force, and the lower the Young's modulus of the elastic body, the easier the elastic body is to flatten, and the wire harness is also easily flattened.

Thus, in the bundled electric wire according to the present invention, the elastic body 2
Since the Young's modulus e of the elastic body 2 is made sufficiently smaller than the Young's modulus E of the electric wire by setting the 50% compressive load of 1000 g / cm ² or less, the elastic body 2 has a low Young's modulus and is flat. The flattening force increases (the flattening force increases as the Young's modulus of the electric wire increases, that is, the bending tensile stress and bending compressive stress increase), and the wire harness is easily flattened. Under such flattening, the bending rigidity (second bending moment of section) becomes small (the second bending moment I of section becomes smaller as the thickness above and below the bending neutral plane becomes smaller. If Young's modulus is E, it is EI),
Easy to bend.

However, due to the interposition of the elastic body 2, the outer diameter of the wire harness increases, and the bending rigidity (second bending moment of section) increases due to this increase. However, the bending rigidity decreases due to the flattening rather than this increase. Minutes are superior, and the bending rigidity of the wire harness as a whole can be reduced to facilitate bending.

Actually, when the elastic body is interposed, the elasticity of ordinary bundled electric wire (outer diameter 25 mmφ) without elastic body is required to bend 90 ° along a mandrel with a radius of 10 cm. 0.46, 400 under a 50% compressive load of 50 g / cm ²
Under g / cm ² in the original 0.31,800g / cm ² was 0.46. On the other hand, except that each wire was twisted at an angle of about 60 °, the other conditions were the same, but the bending force with and without the elastic body was almost the same.

In the present invention, the elastic body may be interposed in the electric wire bundle in a dispersed state.

(Effect of the Invention) The bundled electric wire according to the present invention has the above-described configuration, and the wire bundle can be bent with a small force even though the press-winding tape is wrapped tightly around the wire bundle by the wrap winding. Therefore, it is possible to provide a bundled electric wire that is stable in a bundled state, has excellent water resistance, and is easily bent during wiring work. Further, as compared with the conventional bundled electric wire, it is only necessary to interpose an elastic body in the electric wire bundle, so that the manufacturing is easy.

[Brief description of drawings]

 FIG. 1 is an explanatory view showing an embodiment of the present invention. 1 ... electric wire, 2 ... elastic body, 3 ... holding tape.

Claims (1)

[Scope of utility model registration request] 1. In a wire harness in which a large number of electric wires are bundled by winding a holding tape, an elastic body having a 50% compression load of 30 to 1000 g / cm ² is interposed in the electric wire bundle. A bundled electric wire.