JPS60492Y2 - Protection tube for flexible cable in speedometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a protective tube for a flexible cable, particularly for driving a speedometer of an automobile.

In recent years, flexible cables for driving this type of speedometer have been changing to cables made of synthetic resin.

However, since the inner circumferential surface of the synthetic resin cable inside the protective tube is smooth, the inner flexible shaft (hereinafter simply referred to as the shaft in this specification) tends to dance inside the protective tube, and it is difficult to prevent the inner flexible shaft from dancing inside the protective tube. This was adjusted by reducing the gap between the shaft and the protective tube since there was no effective means available.

However, in the case where the gap between the shaft and the protection tube is reduced in the protection tube as described above, there is a drawback that the outer circumference of the shaft comes into contact with the inner circumference of the protection tube due to a small bend in the cable.

On the other hand, in order to keep the lubricant in the protection tube so that the shaft rotates smoothly without wear, the inner peripheral surface of the protection tube is formed into a hexagonal cross section, and the lubricant is stored in each corner. It held lubricant, but since the surface was smooth in the longitudinal direction, the lubricant moved easily and its function was not fully demonstrated.

The present invention was developed in view of the above points, and its purpose is to form an uneven surface unevenly on the inner circumferential surface of the synthetic resin base tube, thereby effectively lubricating the concave portions of the uneven surface. The lubricant retains the lubricant, thereby preventing the shaft from bouncing around in the synthetic resin base pipe and preventing noise during high-speed rotation.The lubricant also allows the shaft to rotate smoothly without wear, and furthermore prevents the lubricant from draining. ° in speedometer to prevent
To provide protective tubes for flexible cables.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a protective tube through which the shaft 2 is inserted, and 3 is a flexible synthetic resin base tube constituting the protective tube 1, which is made of, for example, polyamide-based synthetic resin.

4 is a braid formed on the outer periphery of the synthetic resin base tube 1, and this braid 4 is made by inserting metal wires into the outer circumferential surface of the synthetic resin base tube 1 so that a coarse portion 5a and a dense portion 5b are formed in the longitudinal direction. It is formed by rolling it up.

Reference numeral 6 denotes an external protective tube formed by coating the outer periphery of the synthetic resin base tube 1 via the braid 4, and is coated by extrusion molding or the like using a polyolefin resin such as polyethylene or polypropylene. Due to the temperature and pressure, the coarse portion 5a and the dense portion 5b of the braid 4 push the synthetic resin base tube 3 in the axial direction, thereby creating an uneven uneven surface 7 on the inner peripheral surface of the resin base tube 3. is formed.

One embodiment of the present invention is constructed as described above, and is formed by winding a metal wire around the outer periphery of the synthetic resin base tube 3 so as to form a coarse portion 5a and a dense portion 5b in the axial direction. When the outer protective tube 6 is coated on the outer periphery of the threat resin base tube 3 via the braid 4, the braid 4 pushes the threat resin base tube 3 in the axial direction, thereby causing the inside of the threat resin base tube 3 to Since the uneven surface 7 is formed on the circumferential surface, the lubricant inside the protective tube 1 is retained in the recesses of the uneven surface 7.

Therefore, the shaft 2 inserted into the synthetic resin base tube 3 of the protective tube 1 is prevented from directly contacting the outer peripheral surface of the synthetic resin base tube 3 by the lubricant, and the shaft 2
rotates smoothly while preventing dancing within the synthetic resin base tube 3.

As mentioned above, the present invention provides a non-uniformly formed uneven surface on the inner peripheral surface of the synthetic resin base tube, and effectively retains the lubricant in the recesses of this uneven surface. The shaft can be prevented from swinging, thereby preventing noise during high-speed rotation, and can also prevent the lubricant from leaking out, and the shaft can be rotated smoothly without wear due to the lubricant.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway slope view showing one embodiment of the present invention;
The figure is also a vertical side view. 1... Protection tube, 2... Shaft, 3.
...Synthetic resin base tube, 4... Braid, 5a.
...Coarse part of braid 4, 5b... Braid 4
Closed part, 6...External protection tube.

Claims (1)

[Scope of utility model registration request] A metal wire is wound coarsely and densely in the longitudinal direction on the outer circumferential surface of a flexible synthetic resin base tube to form a braid, and the outer circumferential surface of the synthetic resin base tube is coated with a flexible synthetic resin to form an external protective tube. A non-uniform uneven surface capable of retaining a lubricant is formed on the inner circumferential surface of the synthetic resin base pipe by forming the inner flexible shaft, and an inner flexible shaft is inserted into the synthetic resin base pipe via the lubricant. Protective tube for flexible cables used in speedometers.