JPH0311451Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a push-pull control cable in which an inner cable is slidably inserted into an outer tube to transmit operating forces in both push and pull directions.

Problems to be solved by conventional technology and ideas In this type of push-pull control cable, a resin liner is usually inserted into the inner circumference of the outer tube, and the inner cable slides inside it. However, if the clearance between the two is made smaller in order to eliminate bumpiness, the sliding resistance when pushing and pulling the inner cable will increase, reducing transmission efficiency, and the inner periphery of the outer tube will wear out prematurely. Therefore, it is necessary to provide a relatively large clearance between the inner cable and the liner. However, if such a clearance is provided, the inner cable will have some play in the radial direction within the outer tube, so when the inner cable is pushed, it may bend within the outer tube, or the outer tube may bend. If the cable is routed, the inner cable will hit the inner periphery of the outer tube when pulling, and conversely will hit the inner periphery of the outer tube when pushing, resulting in looseness and poor operational response. It was not possible to accurately control the stroke, and there were also problems with low operating force transmission efficiency.

Means for Solving the Problems As a means for solving the above problems, the push-pull control cable of the present invention has a push-pull control cable that fits around the outer circumference of the inner cable, and the center part fits almost tightly into the inner circumference of the outer tube. A resin coating having a barrel shape with an outer diameter is fixed at multiple locations at intervals in the length direction.

Functions and Effects of the Invention The present invention has the above-mentioned configuration, and since the resin coating formed on the inner cable can maintain a highly accurate outer diameter dimension, the outer periphery of the resin coating and the inner periphery of the outer casing can be tightly or only slightly connected. It is possible to mate with a clearance of , it is possible to improve operational responsiveness and transmission efficiency, and since the resin coating is barrel-shaped, the contact with the outer tube is a line contact, which keeps sliding resistance to a low level, and the cable can be routed with a small radius. It can slide freely inside the outer tube. Furthermore, the space between the resin coatings can be used as a reservoir for lubricating oil, which further reduces sliding resistance, improves operating force transmission efficiency, and further extends the life of the cable.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIG.

1 is an outer tube with a three-layer structure,
A plurality of thin steel wires 3 are arranged around a liner 2 made of synthetic resin with a small coefficient of friction and formed by extrusion molding.
is tightly wound spirally and its outer periphery is covered with a jacket 4 made of synthetic resin.On the other hand, the inner cable 5 inserted into the outer tube 1 has a plurality of steel wires with a diameter larger than the inner diameter of the liner 2. The inner cable 5 is made of stranded wires twisted together to have a small outer diameter, and on the outer periphery of the inner cable 5 there is a synthetic resin with an outer diameter that fits tightly into the inner periphery of the liner 2, which is also made of synthetic resin with a small coefficient of friction. The covering 7 is fixed by casting at a plurality of locations at regular intervals in the length direction. As shown in the figure, each resin coating 7 has a barrel shape with a swollen central portion in the length direction, so that the contact with the liner 2 is a line contact, resulting in low sliding resistance and a small radius. It can freely slide inside the outer tube 1 where the cables are arranged. In addition, the intervals between the resin coatings 7 are set to such an extent that the portions between the resin coatings 7 of the inner cable 5 do not buckle when the inner cable 5 is pushed and operated, for example, when the inner cable 5 is thin and has low rigidity. Small gaps are used; conversely, when they are thick and rigid, large gaps are used.

When the inner cable 5 formed with this resin coating 7 is inserted into the outer tube 1, the outer periphery of the central part of the resin coating 7 is tightly fitted to the inner periphery of the liner 2 of the outer tube 1. Since there is no play in the radial direction within the outer tube 1, bending or buckling within the outer cable 1 when pushing or pulling the inner cable 5 is avoided.

Note that by filling the space between the resin coating 7 with lubricating oil, the sliding resistance between the resin coating 7 and the liner 2 is reduced, and the inner cable 5 can be pushed and pulled with a small operating force. Further, as shown in the figure, an oil reservoir groove 8 may be formed on the inner circumferential surface of the liner 2.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention. 1: Outer tube, 2: Liner, 5: Inner cable, 7: Resin coating.

Claims (1)

[Scope of utility model registration request] In a push-pull control cable in which an inner cable is slidably inserted into an outer tube to transmit operating force in both push and pull directions, the inner cable has a central portion approximately tightly attached to the inner circumference of the outer tube. A push-pull control cable characterized in that barrel-shaped resin coatings with mating outer diameter dimensions are fixed at multiple locations at intervals in the length direction.