JPH01279108A - Meter cable sheathing structure - Google Patents

Abstract

PURPOSE:To improve sheath layers in tensile strength by braiding high tension fiber impregnated with adhesive resin on outer side of an inner sheath having a housing space for flexible rotary shaft, and forming an outer sheath layer adhered and combined with high tension fiber via resin. CONSTITUTION:High tension of fiber 2 such as polyamide fiber is braided and set on outer side of an inner sheath 1. The fiber 2 is impregnated with thermofusible and adhesive resin 3 such as mixture of polypropylene and polyamide, and each fiber filament is adhered together while many lumps 3 of resin are formed on outer side of the fiber 2. Molten resin such as synthetic rubber is injected into a metal mold over the braided and set polyamide fiber 2 for forming an outer sheath layer 4. Therefore, the fiber 2 is made in one body with the sheath layer 4 through remelting of the lumps 3 of resin, and at the same time, the sheath layer 4 and the inner sheath 2 also are adhered and set together. As a result, the sheath layer 4 gets strong in tensile strength or temperature change.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a covering structure for a meter cable that accommodates a flexible rotating shaft.

[Conventional technology]

In order to transmit the rotation of a transmission of a vehicle or the like to a speedometer or the like, a meter cable is used in which a flexible rotating shaft is inserted into a conduit. Conventionally, the covering structure of this meter cable was to wind a narrow metal plate into a coil to form a hollow and flexible inner sheath, and a flexible rotating shaft was attached to the hollow part of the inner sheath. It is known that a fiber cable reinforcing material is braided on the outside of the cable, and a covering layer is formed by injection molding a resin such as molten synthetic rubber thereon. In this case, high tensile strength materials such as polyaramid fibers and wires are usually used as cable reinforcements.

(Problem to be solved by the invention) However, in such conventional technology, since the reinforcing material and the coating resin are different, slippage occurs between the image materials when high tension is applied to the cable. , only the coating resin part stretches.Also, because the linear expansion coefficients of the painting materials are different, slippage occurs as above due to temperature changes around the meter cable, and the inner sheath and coating layer There was a problem in that the lengths of the wires were misaligned, making it difficult to use in areas where there are temperature changes.To solve this problem, multiple coating layers were stacked to increase the frictional resistance between each layer. Although there are some methods, the formation of the covering layer becomes complicated and causes an increase in cost.

Furthermore, when wire is used as a reinforcing material, it is easy to transmit vibrational sounds such as rotational hammering sounds generated when the flexible rotating shaft rotates within the inner sheath, creating a noise problem and not meeting market needs. There was also the problem.

The present invention has been made in view of the above facts, and an object of the present invention is to provide a meter cable that has a coated structure that is resistant to temperature changes and tensile forces, and that is difficult to transmit vibration noise.

[Means to solve the problem]

In order to achieve the above object, the meter cable sheathing structure according to the present invention is provided by knitting high tensile strength fibers impregnated with an adhesive resin on the outside of an inner sheath having an accommodation space for a flexible rotating shaft. The structure includes an outer coating layer that is adhesively bonded to the high tensile strength fibers via an adhesive resin.

[Example] An example of the present invention will be described with reference to the drawings. 1st
The figure is a partially cutaway view showing a meter cable according to the present invention.
FIG. 2 is a sectional view taken along line A--A in FIG. 1. In these figures, l denotes an inner sheath, which is formed by winding a narrow metal plate into a coil shape so as to be hollow and flexible. Reference numeral 2 is a high tensile strength fiber braided into a net shape, which serves as a reinforcing material for the covering layer, and in the embodiment of the present invention, a structure comprising a large number of thin filaments of polyaramid fiber is used. Polyaramid fibers have excellent properties such as high tensile strength and not softening or melting even at high temperatures. As the reinforcing high tensile strength fibers, it is also possible to use fibers such as glass fibers and carbon fibers in addition to the polyaramid fibers. This polyaramid fiber 2 is
It is impregnated with another resin, for example, a hot-melt, strong adhesive resin such as a mixture of polypropylene and polyamide.
At the same time that the resin penetrates between the filaments and adheres to each other, a large number of resin lumps 3 are formed on the outside of the polyaramid fibers 2. In this way, the polyaramid fibers 2 impregnated with the branches (fat 3) are braided on the outside of the inner sheath 1 and set in a mold (not shown), and then a resin such as synthetic rubber molten with an extrusion molding machine is poured onto it. The polyaramid fibers 2 are sandwiched between the inner sheath 1 and the synthetic rubber, and are injected to form the outer sheath N4.The polyaramid fibers 2 not only bite into the synthetic rubber outer sheath N4, but also inject the resin and the resin impregnated into the polyaramid fibers 2. , the resin mass 3 is melted again, and the polyaramid fibers 2 and the covering layer 4 are bonded and integrated.The melted adhesive resin 3 also permeates between the covering layer 4 and the inner sheath 1 at the same time, bonding them together. Fix with adhesive.

In this way, since the polyaramid fiber 2 as a reinforcing material and the outer coating layer 4 are bonded, the polyaramid fiber 2 compensates for the weaknesses such as thermal expansion and tensile strength of the resin forming the coating N4, and is resistant to temperature changes and tensile strength. A strong cable sheathing structure can be achieved.

According to the embodiments of the present invention, compared to the case where the conventional reinforcing material and the outer coating layer are not bonded,
The expansion and contraction of the meter cable outer coating layer was 0.8% in the longitudinal direction with respect to the temperature change in C.2, but by implementing the present invention, the expansion and contraction in the longitudinal direction was reduced to 0.2% or less, even in locations with large temperature changes. Now it can be used stably. Furthermore, compared to the case where a wire is used as the reinforcing material, the one using the polyaramid fiber 2 has better vibration absorption, so the -3 dBJ attenuation rate is improved for vibrations of 0 to 5 kHz.

Furthermore, for the same reason, the soundproofing properties were also increased by 5 dB.

The coating structure of the present invention is a technology that can also be applied to the coating structure of -a electric wires and optical fiber cables.

[Effects of the Invention] As explained above, according to the present invention, in the cable sheathing structure, the resin forming the outer sheathing layer and the high tensile strength fibers serving as the reinforcing material of the N layer are joined. Therefore, it is possible to obtain a meter cable covering structure that has little expansion and contraction due to temperature changes, high tensile strength, and high vibration sound attenuation. Furthermore, there is no need to stack a large number of coating layers, making it possible to reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway view of a meter cable showing one embodiment of the present invention, and FIG. 2 is a cross section M taken along line A--A in FIG. 1. DESCRIPTION OF SYMBOLS 1... Inner sheath, 2... High tensile strength fiber, 3... Impregnated resin, 4... Outer coating layer. Patent applicant Yazaki Sogyo Co., Ltd. Cable Technica Co., Ltd. A Figure 2

Claims (1)

[Claims] High tensile strength fibers impregnated with an adhesive resin are braided on the outside of an inner sheath having a housing space for a flexible rotating shaft, and an outer covering layer is formed which is adhesively bonded to the high tensile strength fibers via the adhesive resin. A cable sheathing structure characterized by: