JP2001124047A - Push-pull control cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a push-pull control cable capable of maintaining a high load efficiency for a long period of time and serviceable even under severe service conditions such that it is bent abruptly with a small curvature. SOLUTION: The push-pull control cable is structured so that an inner cable 12 is slidably threaded through an outer tube 4 and the force in push and pull directions given to one end of the inner cable 12 is transmitted to its other end. The inner cable 12 is formed from a core 14, main side wires 16a wound spirally round the core, and a coating layer 18 covering their surfaces 18. In particular, the main side wires 16a are separated from one another, and the coating layer 18 has approximately a constant thickness, and a spiral groove 19 is provided at the surface of the coating layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control cable capable of performing both a push operation and a pull operation.
The present invention relates to a push-pull control cable that can maintain high load efficiency over a long period of time and has excellent durability.

[0002]

2. Description of the Related Art There is known a control cable in which a resin coating layer is formed on the surface of an inner cable to reduce the contact resistance with the inner surface of an outer tube to realize high load efficiency. -88934. In the cable disclosed in Japanese Patent Application Laid-Open No. 9-88934, both the surface of the inner cable and the inner surface of the outer tube are made of resin to reduce the contact resistance.
The load efficiency referred to here is a ratio of the load applied to one end of the inner cable to the load transmitted to the other end of the inner cable in a state where the outer tube is fixed, and the ratio between the surface of the inner cable and the outer tube. Higher load efficiency is obtained as the contact resistance with the inner surface is lower.

In the case of a control cable, not only high load efficiency is required, but also high load efficiency needs to be maintained for a long period of time. Therefore, a control cable described in Japanese Patent Application Laid-Open No. 4-92110 has been developed. In the control cable described in this publication, both the surface of the inner cable and the inner surface of the outer tube are made of resin, thereby realizing a low contact resistance and maintaining a low contact resistance state for a long period of time. Then, the surface of the inner cable is coated with a resin so that a spiral groove remains on the surface of the coating layer constituting the inner cable surface. According to this technology, high load efficiency is realized by the resin surface, and the lubricant is held for a long time by the spiral groove, and the high load efficiency is held for a long time.

[0004]

SUMMARY OF THE INVENTION The present inventors have disclosed in
As a result of a detailed study of the technique described in JP-A-92110, it was found that the load efficiency could still be increased and the durability could still be improved. The present invention provides a push-pull control cable that achieves high load efficiency by coating the inner cable surface with a resin, and increases the holding capacity of the lubricant by leaving a spiral groove on the surface of the coating layer. It is an object to improve the load efficiency so that the durability can be further improved.

[0005]

A push-pull control cable according to the present invention comprises an outer tube in which an inner cable is slidably inserted, and a push-pull direction applied to one end of the inner cable. Is transmitted to the other end of the inner cable. The inner cable has a core wire, a main side wire spirally wound around the core wire, and a coating layer covering the surface. In the push-pull control cable of the present invention, in particular, the spiral-wound main side lines are separated from each other, the coating layer has a substantially constant thickness, and a spiral groove is formed on the surface of the coating layer. It is characterized by.

The term "main side line" as used herein means a side line for determining the outer diameter of the inner cable. In addition to the main side line, a sub-side line having a smaller diameter may be used in combination. It may be configured. In any case, in the control cable of the present invention, the main side wires are spirally wound at a distance from each other without being in contact with each other in a spirally wound state.

[0007] The control cable is coated on the surface of the inner cable and realizes high load efficiency. Further, spiral grooves are formed on the surface of the coating layer, so that the ability to hold the lubricant is high and the durability is high. In particular, the main side lines spirally wound around the core wire are separated from each other so as to be in a non-contact state, and in this state, the layer thickness is covered with a coating layer having a substantially constant thickness. The spiral groove formed in the space can be made sufficiently deep and wide, and the ability to hold the lubricant can be further enhanced, thereby achieving higher load efficiency and higher durability.

[0008] Moreover, in this control cable,
The difference between the outer diameter of the inner cable and the inner diameter of the outer tube can be reduced as much as possible while ensuring sufficient lubricant holding capacity. The play of the control cable (by pushing or pulling one end of the inner cable The distance between the distance and the distance at which the other end of the inner cable is extruded or retracted) can be reduced as much as possible, and the movement at one end is accurately transmitted to the other end. However, the force required for the operation can be kept low. For this,
It is possible to realize a push-pull control cable that can be used in severe use conditions, such as when the control cable is bent with a small radius of curvature.

As a result of the research conducted by the present inventors, it has been found that particularly preferable results are obtained when the depth of the groove formed on the surface of the coating layer is 0.077 to 0.115 times the diameter of the inner cable. Was. It was confirmed that the lubricant holding capacity was insufficient at 0.0077 or less, and the contact area between the inner cable surface and the outer tube inner surface decreased and the contact surface pressure increased at 0.115 or more, causing problems in load efficiency. .

[0010]

FIG. 1 shows a push-pull control cable 2 according to an embodiment of the present invention.
, The inner cable is shown in appearance, and the other members are shown in cross section. FIG. 2 shows a cross section taken along line II-II of FIG. 1, and FIG. 3 shows a cross section taken along line III-III of FIG.
The outer tube 4 has a three-layer structure. The innermost layer is a liner 6 made of resin, the intermediate layer is a shield 8, and the outermost layer is an outer coat 10. The liner 6 is formed in a tubular shape with a resin having excellent lubrication, such as polyphenylene sulfide, polytetrafluoroethylene, polyoxymethylene, polybutylene terephthalate, polytrifethylene, olefin, and polyamide. The shield 8 is composed of a number of steel wires 8a spirally twisted around the liner 6 without any gap therebetween, and the outer periphery thereof is covered with an outer coat 10 made of resin.

The inner cable 12 is wound around the core wire 14 between the adjacent main side wires 16a, and a total of five or eight main side wires 16a spirally wound around the core wire 14. 5 or 8 sub-side lines 16b in total
And a resin coating layer 18 covering the surface with a substantially uniform thickness. The core wire 14 is formed of one steel wire, but may be formed of a stranded wire. Each of the main side wires 16a is made of a steel wire, but may be made of a stranded wire. Each sub-side line 16b is made of a steel wire, but may be made of a stranded wire. The coating layer 18 was composed of 66 nylon, but was composed of other resins having excellent lubricity such as polyphenylene sulfide, polytetrafluoroethylene, polyoxymethylene, polybutylene terephthalate, polytrifuctaethylene, olefin and polyamide. Is also good. The coating method is
An electrostatic powder coating method, a solvent coating method and the like are preferably used. Alternatively, a resin may be extruded around the core wire and the side wire to cover the surface.

An inner cable according to the embodiment was prepared with the following two types of wire diameters. In each case, the diameter of the inner cable is 2.6 mm. In each case, a spiral groove 19 was formed on the surface of the coating layer. Core wire diameter Side wire diameter (number) Secondary wire diameter (number) Coating thickness Groove depth 1.4mm 0.4mm x 8 0.2mm x 8 0.2mm 0.2mm 1.0mm 0.6mm x 5 0.3mm x 5 0.2mm 0.3mm Groove 19 for diameter of inner cable 12
Was 0.077 times and in the latter case 0.115 times.

For the purpose of comparison, various types of cables having a groove depth other than 0.077 to 0.115 times the inner cable diameter were prepared. With respect to these cables, the initial load efficiency and the change in load efficiency generated when the push-pull operation was repeated were measured. As a result, it was confirmed that when the depth of the groove was 0.077 times or less, the holding ability of the lubricant was reduced, and the load efficiency was reduced when the number of push-pull operations was relatively small. On the other hand, when the depth of the groove was 0.115 times or more, it was confirmed that the contact area between the inner cable surface and the inner surface of the outer tube was reduced, the contact pressure was increased, and the initial load efficiency was low. In order to maintain high load efficiency over a long period of time, the groove depth should be 0.077 to the inner cable diameter.
It has been found that it is advantageous to set the range to about 0.115 times.

FIG. 5 shows the measurement results. The horizontal axis indicates the depth of the groove in terms of the ratio to the diameter, the left vertical axis indicates the initial load efficiency, and the right vertical axis indicates an index relating to durability (in this case, the load efficiency drops to 90% of the initial value). The solid curve shows the relationship between the depth of the groove and the initial load efficiency, and the dashed line curve shows the number of operations at which the groove depth and the load efficiency fall to 90% of the initial value. Shows the relationship. It was confirmed that by setting the depth of the groove in the range of 0.077 to 0.115 times the diameter, high load efficiency was secured for a long time.

In FIG. 1, reference numeral 20 denotes a mounting flange, which is fixed to one end of the outer tube 4. The mounting flange 20 is fixed to a vehicle body or the like, and the position and direction of the end of the control cable 2 are fixed. 22
Indicates a sleeve, and a ring-shaped convex portion 2 formed at the base.
2a is a ring-shaped recess 20 formed in the flange 20
By fitting into a, the tip of the sleeve 22 can swing freely as shown by the arrow X.

Reference numeral 24 denotes an eye rod, which is slidable in the sleeve 22 and one end of the inner cable 12 is fixed. By sliding in the sleeve 22, one end of the inner cable 12 is pulled or pushed.
A large diameter hole 24b is provided at the tip of the eye rod 24,
A thin wall 24a is formed therearound. The inner cable 12 in which the coating layer 18 is removed near the end and the inner cable 12 from which the coating layer 18 is removed and the main side line 16a and the sub side line 16b are exposed is formed in the hole 2
4b, and one end of the inner cable 12 is fixed to the eye rod 24 by caulking the thin wall 24a from the outside. 24c is a hole having a small diameter for sufficiently caulking, and 24d is a hole for connecting the eye rod 24 to, for example, a swinging shift lever.

In the case of this connection structure to the eye rod 24,
Since the main side line 16a is separated, the main side line 16a can be largely deformed by caulking the thin wall 24a from the outside. In addition, the coating layer 18 is removed at the insertion portion into the eye rod 24. Therefore, the outer diameter of the eye rod 24 can be made substantially equal to the outer diameter of the inner cable 12 despite the existence of the thin wall 24a. (However, the outer diameter of the inner cable 12 at the portion inserted into the eye rod 24 is the main side line 16 which has been separated because the coating layer 18 has been removed and the outer wall 24a has been caulked.
In order to deform so that a fills the space where a was separated,
It is more contracted than the outer diameter of the eye rod 24. Main side line 16
The main side line 16a is greatly deformed because a is separated,
The diameter of the inner cable is greatly reduced as compared with the case where the main side wires are in close contact with each other. As a result, the outer diameter of the inner cable 12 sliding in the outer tube and the eye rod 24 are reduced.
Can have almost the same outer diameter. )

As described above, since the outer diameter of the inner cable 12 is substantially equal to the outer diameter of the eye rod 24,
The inner diameter of the flange 20 and the inner diameter of the sleeve 22 can be made substantially equal to the inner diameter of the outer tube 4. For this reason, the clearance between the inner cable 12 and the flange 20 and the clearance between the inner cable 12 and the sleeve 22 within the length range in which the inner cable 12 protrudes from the outer tube 4 and is surrounded by the flange 20 and the sleeve 22. Between the inner cable 12 and the outer tube 4
A small clearance substantially equal to the clearance between the inner cable 12 and the inner cable 12 can be prevented from buckling in the clearance between the flange 20 and the sleeve 22 when the inner cable 12 is pushed.

If the main side wires are in contact with each other as in the prior art, the main side lines cannot be sufficiently deformed even when swaged in the eye rod 24, and the diameter of the inner cable 12 can be reduced by the thickness of the wall 24a. However, the diameter of the eye rod 24 had to be larger than the diameter of the inner cable 12 sliding in the outer tube 4. For this reason, the inner diameters of the sleeve 22 and the flange 20 also increase, and the clearance between the inner cable 12 and the flange 20 and the clearance between the inner cable 12 and the sleeve 22 also increase. Was easily buckled in the clearance between the flange 20 and the sleeve 22. The push-pull control cable of the present embodiment is improved so that it does not easily buckle during a push operation.

FIG. 4 shows another embodiment of the structure for attaching the inner cable 12 to the eye rod 24. In this mounting structure, the eye rod 24 is provided with two-stage inner cable insertion holes 24e and 24f. Hole 2 at the back
Reference numeral 4f denotes a small diameter, and the thickness of the wall 24h is such that the inner cable 12 is sufficiently swaged and fixed. The front hole 24e is larger in diameter than the inner hole 24f by the thickness of the coating layer 18, and its wall 24g is thinner by the thickness of the coating layer 18. 24 g of this wall is coated layer 18
The inner cable 12 is connected to the eye rod 2
Because it is not connected to 4, it is extremely thin. The diameter of the hole 24e is substantially equal to the diameter of the inner cable 12 having the coating layer 18, and the diameter of the hole 24f is substantially equal to the diameter of the inner cable 12 having no coating layer 18.

Here, the coating layer 18 is formed at the tip.
The inner cable 12 from which is removed is inserted into the hole 24f, and the walls 24g and 24h are caulked. The inner cable 12 from which the coating layer 18 has been removed is inserted into the hole 24f, and the inner cable 12 having the coating layer 18 is inserted into the hole 24e. The inner cable 12
It is connected to the eye rod 24 mainly by caulking the thick wall 24h.

In this case, a clearance corresponding to the thickness of the wall 24g is generated between the inner cable 12 and the sleeve 22. However, since the wall 24g is extremely thin, the clearance is small, and it is possible to prevent the inner cable 12 from buckling in the clearance.

In the above-described embodiment, the sub-side line 16b having a smaller diameter than the main side line 16a is disposed between the main side lines 16a.
a are separated from each other so as not to contact each other. However, the secondary side line 16b can be omitted, and the secondary side line 16b can be omitted.
The push-pull control cable can be spirally wound so that the main side wires 16a do not come into contact with each other without using a wire. In this case, a push-pull control cable which can maintain a small play and a high load efficiency for a long period of time is realized. Is done.

According to the inner cable according to the present embodiment, it works so as to suppress buckling of the coating layer on the surface, and a push-pull control cable having the same performance can be configured with a smaller diameter than that of the conventional technique.
Further, since the load efficiency is high and the state where the load efficiency is high is maintained for a long period of time, the diameter of the inner cable can be further reduced.

Further, according to the present embodiment, since the large spiral groove holds the lubricant, the difference between the substantial outer diameter of the inner cable and the inner diameter of the outer tube can be reduced without impairing high load efficiency. As small as possible, play can be reduced. For this reason, according to the control cable of the present invention, when the operating lever for switching the transmission and the shift operating lever are connected when the wiring condition is severe, each shift position is required between the shift operating lever side and the transmission side. Position displacement can be prevented, and the practical value is extremely high.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a control cable according to an embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a diagram showing a modification of the structure for attaching the inner cable to the eye rod.

FIG. 5 is a diagram showing the relationship between initial load efficiency, durability, and groove depth.

[Explanation of symbols]

 2: Control cable 4: Outer tube 12: Inner cable 14: Core wire 16a: Main side wire 18: Coating layer

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Hamaguchi Naomi-cho, Midori-ku, Nagoya-shi, Kami-cho, 68-Chuo Hatsujo Co., Ltd. F term (reference) 3J032 AB01 AB40 BA06

Claims (2)

[Claims] 1. A push-pull control cable for slidably inserting an inner cable into an outer tube and transmitting a push-pull bidirectional force applied to one end of the inner cable to the other end of the inner cable. A core layer, a main side line spirally wound around the core line, and a coating layer covering the surface, the spirally wound main side line is separated from each other, the coating layer has a substantially constant thickness, A push-pull control cable, wherein a spiral groove is formed on the surface of the layer. 2. The push-pull control cable according to claim 1, wherein the depth of the groove formed on the surface of the coating layer is from 0.077 of the inner cable diameter.
Push-pull control cable characterized by being 0.115 times.