JPS6327138Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an inner cable of a push-pull cable in which the inner cable is slidably inserted into the outer tube to transmit operating force in both push and pull directions. Inner cables for push-pull cables with excellent inner cables have various structures, among them a single steel wire made of oil-tempered steel or stainless steel, or a steel wire with a core wire surrounded by fine steel. Twisted wires made of spirally wound wires have the advantage of having higher buckling strength and less elongation and shrinkage than those made of twisted thin steel wires, and are thus prized. However, when the inner cable of such a structure slides along the curved outer tube, large bending stress (tensile stress and compressive stress) is applied to the steel wire, so the mechanical strength, especially It has the disadvantage of poor durability against repeated bending stress. The object of the present invention is to eliminate such drawbacks and provide an inner cable for a push-pull cable that has high buckling strength and excellent bending strength.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figures 1 and 2 show the state in which swaging is applied to the surface of a steel wire 1 such as an oil-tempered steel wire or a stainless steel wire, in which eight semicircular concave surfaces b are formed on the inner peripheral surface. A roller c is rotatably fitted into each of the semicircular concave surfaces b of the fixing ring a, which are formed at equal angular intervals. A rotary frame d with through holes e formed on both end faces is attached to the center of the fixed ring a, and a pair of mutually opposing blocks f, f slide in the radial direction within the rotary frame d. Freely fitted. At the center of the corresponding inner surface of each block f is a pressing surface g with an approximately semicircular cross section.
is formed, device holes h are formed on both sides of the striking surface g, and a spherical concave surface i is formed in the center of the outer peripheral surface, and elastic expansion of the compression coil spring j fitted in each device hole h is formed. The pair of blocks f are urged away from each other by the force, as shown by the chain lines in FIG. It protrudes to its outer surface through e. Then, when the rotating frame d is rotated at a high speed while passing the steel wire 1 between a pair of opposing pressing surfaces g and moving the steel wire 1 in one direction at a slow speed, the first
A steel ball k protrudes from the through hole e as shown by the solid line in the figure.
When engaged with roller c, the pair of blocks f move toward the center against the elasticity of compression spring j, strongly pressing the outer circumferential surface of steel wire 1 with pressing surfaces g and g, and the chain line in the figure As shown, steel ball k is connected to roller c
At rotation angles that do not engage with the blocks f, f
are separated from each other by the elastic expansion force of the compression spring j, and the blocks f and f repeat separation and approach four times for each revolution of the rotating frame d, and move the outer peripheral surface of the steel wire 1 at high speed. Apply swaging by applying strong pressure. The steel wire 1 that has been swaged in this way has compressive residual stress on its surface, and moreover, unlike shot peening, no dents are formed on the surface, and the surface is Because it is extremely smooth, the fatigue strength is significantly improved, and the repeated bending strength is 4 to 5 when compared with shot peening when the magnitude and depth of residual stress are the same. It was experimentally confirmed that the improvement was doubled.

However, when this steel wire 1 is used alone, it has the disadvantage that the bending rigidity is too high, resulting in low load transmission efficiency and poor operational feeling. Therefore,
Figures 3 to 6 show some embodiments in which the steel wire 1 is made slightly smaller in diameter and the bending rigidity is reduced by spirally winding a fine steel wire around it to form a stranded wire. The example in Fig. 3 has a large number of fine steel wires 2 tightly wound spirally around the steel wire 1 having the above structure, and has excellent flexibility, and the example in Fig. 1
It is made by spirally winding the thin steel wire 3 with a coarse pitch, and has an oil pool, so it has excellent lubricity.
The example in the figure is a spirally wound thin steel wire 3 in the example in Figure 4 on the example in Figure 3, which has the advantages of both.
The example in Figure 6 is a thin steel wire 4 with a rectangular cross section in addition to the example in Figure 3.
It has the advantage of being tightly wound and has excellent restorability.

As specifically explained in the above embodiments, the inner cable of the push-pull cable of the present invention has a core wire made of a steel wire whose surface has been smoothly swaged to generate compressive residual stress, and a thin wire surrounding the core wire. The main feature is that it is made of stranded steel wire spirally wound, and has the advantages of high buckling strength and low elongation and shrinkage, as well as smooth swaging of the surface to generate residual stress. This significantly improves fatigue strength against bending stress, resulting in excellent durability.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the present invention, and FIGS. 1 and 2 show the steel wire 1 being swaged.
The figure is a sectional view, Figure 2 is an exploded perspective view of the main parts, and Figures 3 to 6 show various types of inner wires made of twisted wires made by spirally winding thin steel wires 2 to 4 around the steel wire 1 as a core wire. It is a perspective view of a cable. 1...Steel wire, 2 to 4...Thin steel wire, a...Fixing ring, c...Roller, d...Rotating frame, f...
Block, k... steel ball.

Claims (1)

[Scope of utility model registration request] In the push-pull cable, the inner cable is slidably inserted into the outer tube to transmit operating force in both push and pull directions, and the inner cable is made of steel whose surface is smoothly swaged to generate compressive residual stress. The inner cable of a push-pull cable is characterized by being made of a stranded wire with a thin steel wire spirally wound around the core wire.