JPH0726646B2 - Push-pull control cable - Google Patents

Description

TECHNICAL FIELD The present invention relates to a push-pull control cable. More specifically, the clearance between the conduit and the inner cable was reduced without reducing the transmission efficiency and durability of the pushing force and pulling force, thereby reducing backlash and improving the buckling load. Regarding control cables.

[Prior Art] A control cable is generally composed of a flexible conduit and one flexible inner cable inserted into the conduit, and one end of the inner cable is pulled or pushed. , By rotating or combining them,
This is to remotely control a driven device attached to the other end of the inner cable.

Of the control cables, the inner cable of the control cable dedicated to pulling is primarily concerned with flexibility, so only metal strands are twisted together without using a core metal. Since a compressive force acts on the inner cable of the control cable, the buckling load is increased, and as shown in Figs.
A core bar (3) having a surplus diameter is used, and a large number of strands (5) are wound around the core bar (3).

In the push-pull operation control cable,
In order to ensure smooth sliding of the inner cable, which has a higher rigidity than the inner cable for pulling, inside the conduit, the clearance between the conduit and the inner cable ((inner diameter of conduit)-(outer diameter of inner cable)) ) Is provided. For example, a conventional push-pull control cable typically has a 0.5
Unless a clearance of mm or more is provided, the force transmission efficiency and durability that can withstand practical use cannot be obtained.

[Problems to be Solved by the Invention] In the conventional push-pull control cable, since the clearance is large, backlash (that the driven side does not accurately follow the push-pull operation amount) becomes large, and manual push-pull operation is performed. There is a large amount of backlash, and the input operation is not accurately transmitted to the driven side, and the operation feeling becomes poor. Further, since the clearance is large, there is a problem that the buckling load is not large enough.

That is, in the inner cord of the conventional structure, if the clearance is reduced, the force transmission efficiency and the like are reduced, so that the backlash is large, and the drawback is inevitable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a push-pull control cable that solves the conventional problems and does not reduce the force transmission efficiency even if the clearance is reduced.

[Means for Solving the Problems] The control cable of the present invention will be described with reference to FIG. 1. The present invention provides an inner cable (2) to be inserted into a conduit (1).
However, the cored bar (3) made of one steel wire having good linearity and the cored bar (3) so that the direction of the strand (5) appearing on the surface is substantially parallel to the longitudinal direction of the inner rope. A normally twisted strand (4) wrapped around the.

The strand (4) is a strand of several strands (5) twisted together, and the strand (4) of ordinary twist is a twist of the inner cord (2) as shown in FIG. 2, for example. Direction (winding direction of the strand (4) (arrow (A) direction)) and twisting direction of the strand (4) itself (strand (5))
A strand that is opposite to the winding direction (direction of arrow (B)) of. In this case, the strands (5) appear almost parallel to the longitudinal direction of the inner cable (2). In the case of rung twisting in which the twisting direction of the inner cord (2) is the same as the twisting direction of the strand (4) itself, as shown in FIG. 11, the strand (5) is the inner cord (2). Although it appears to intersect in the longitudinal direction of No. 1, such rung twist is not used in the present invention. The strand (4) may be wound around the core metal (3) in the Z twist shown in FIG. 3 or in the S twist shown in FIG.

[Working] Conventionally, as an inner cable of a push-pull control cable, there has been no known method of twisting strands to form a strand and winding the strand around a core metal in a normal twist.

For general pulling ropes, in the case of rung twisting, the length of the strands that appear on the surface is long and the surface of the rope is smooth, so the contact area is large and there is less friction.
Also, it is known that the angle formed by the strands with the central axis of the rope is much larger than in the case of ordinary twisting, so that the resistance to bending is small and the flexibility is high. Also, in the case of ordinary twist, the bending of the strands that appear on the rope surface is large and there are relatively many irregularities. For this reason, it is known that the contact area becomes small and the strands tend to be locally painful, so that the durability tends to be poor.

As for the inner cable of the push-pull control cable, there was no one with a normally burning strand, and the knowledge about general ropes mentioned above was inherited as it is. It is speculated that the inner cord used was not adopted.

However, as a result of experiments conducted by the inventors of the present invention on the inner cable involved in the present invention using a normally twisted strand, surprisingly, when it is used by inserting it into the conduit of the control cable, the clearance is high even if the clearance is reduced. The result shows that the transmission efficiency can be achieved and the durability is also excellent.

[Example] Next, the control cable of the present invention will be described in detail together with an example.

FIG. 1 is a structural explanatory view of a control cable of the present invention,
FIG. 2 is an explanatory diagram showing the types of twisting of the strand (4),
3 to 4 are explanatory views showing the twisting direction of the inner rope (2) (that is, the winding direction of the strand (4)), and FIGS.
The figures are cross-sectional views and side views of the inner cable (2) related to Example 1, respectively, and FIGS. 7 to 9 are cross-sectional views of the inner cable (2) related to Examples 2 to 4, and FIGS. 10 to 11, respectively. A cross-sectional view and a side view of the inner cable of Comparative Example 1, FIGS. 12 to 13 are cross-sectional views and a side view of the conventional inner cable described as Comparative Example 2, and FIGS. 14 to 15 are respectively described as Comparative Example 3. A cross-sectional view and a side view of a conventional inner cable, and FIGS. 16 to 19 are explanatory views of an apparatus for measuring the mechanical performance of the inner cable, respectively.

As the core metal (3) in the present invention, those conventionally used can be used without particular limitation, but those having good linearity, that is, those having good spring property are preferable. Examples of such a core metal (3) include metal wires such as steel wire, stainless steel wire, oil tempered wire and brewing wire, or non-metal wires such as ceramics wire and FRP wire, but especially oil. A tempered wire is preferred. The core metal (3) may be composed of only one core wire as shown in FIG.
Further, as shown in FIG. 9, a cored bar (3) may be constructed by winding several strands (3b) around one cored line (3a). The core wire (3a) and the wire (3b)
As the core wire (3a), it is preferable to use an oil tempered wire as the core wire (3a), although any of those conventionally used can be used.

As the strand (4), twisted strands (5) that have been conventionally used can be used without particular limitation,
For example, steel wire, stainless steel wire, or those plated with zinc or nickel are used. There is no particular limitation on the number of strands (5) that compose the strand (4), and it is normally used within a range of about 5 to 22 strands such as 7 strands, 12 strands and 19 strands, but a larger number of strands is used. Line (5)
May be used.

Such a strand (4) is wound around the core metal (3) in the direction opposite to the twisting direction to form an inner cord (2) having a normally twisted strand (4). The strands (4) may be Z-twisted or S-twisted as long as the twisting and winding directions are opposite to each other.

The inner cord (2) obtained as in the above step is inserted into the conduit (1) and assembled into one control cable as shown in FIG. The conduit (1) has a liner (6) made of synthetic resin, which is excellent in self-lubricating property and abrasion resistance, inside. Examples of the synthetic resin include polytetrafluoroethylene, polybrene terephthalate, polyacetal, and polyethylene.

Next, Examples 1 to 3 of the control cable configured as described above will be described in comparison with Comparative Examples 1 to 3.

Example 1 (refer to FIGS. 5 and 6) As the core metal (3), one oil tempered wire having a diameter of 1.6 mm was used, and as the strand (4), seven galvanized steel wires having a diameter of 0.35 mm ( 5) is twisted into Z twist, and 7 strands (4) are placed around the core metal (3).
The inner strand (2) shown in FIGS. 5 and 6 was obtained by winding the S strand at a pitch of 17.5 mm. Inner rope after swaging (2)
Had a diameter of 3.5 mm. A conduit (1) provided with a liner (6) molded of polytetrafluoroethylene and having an inner diameter of 3.7 mm is prepared, and silicone grease is provided inside the conduit (1) around the inner cord (2). Coated and inserted.

Example 2 (see FIG. 7) Similar to Example 1 except that the strand (4) is formed from 12 galvanized steel wire strands (5) having a diameter of 0.27 mm, it is shown in FIG. I got the inner rope (2). The diameter after swaging is 3.5 mm. The conduit (1) was the same as that used in Example 1, and the inner diameter of the liner (6) was 3.7 mm.

Example 3 (see FIG. 8) As strands (4), six wire rods each having a diameter of 0.22 mm were wound around a wire rod having a diameter of 0.24 mm and each of which had a diameter of 0.22 mm. The inner cord (2) shown in FIG. 8 was obtained in the same manner as in Example 1 except that 12 strands of the twisted strand were used. The diameter after swaging was 3.5 mm. The conduit (1) was the same as that used in Example 1, and the inner diameter of the liner (6) was 3.7 mm.

Comparative Example 1 (see FIGS. 10 to 11) The same procedure as in Example 1 was repeated except that the strand (5) and the strand (4) were twisted together into a Z twist to form a rung twist.
The inner cord (2) shown in Fig. 11 was obtained. The same conduit (1) as in Example 1 was used.

Comparative Example 2 (see FIGS. 12 to 13) The core metal (3) is one oil-tempered wire having a diameter of 2.0 mm, and the 12 metal wires (5 having a diameter of 0.6 mm around the core metal (3). ) Was wound in the S twist direction to obtain the inner cord (2) shown in FIGS. 12 to 13. The inner cord (2) has a diameter of 3.2 mm.
The conduit (1) was the same as that used in Example 1, and the inner diameter of the liner (6) was 3.7 mm.

Comparative Example 3 (see FIGS. 14 to 15) The core metal (3) is one oil-tempered wire having a diameter of 1.6 mm, and 15 core wires (5a having a diameter of 0.35 mm are arranged around the core metal (3). ) Is wound in the Z twist direction, and the diameter is further applied
Wrap 16 0.5mm wires (5b) in the S twist direction
The inner cord (2) shown in Figures 4 to 15 was obtained. The diameter of the inner cable (2) after swaging is 3.2 mm. The conduit (1) was the same as that used in Example 1, and the inner diameter of the liner (6) was 3.7 mm.

With respect to the control cables of Examples 1 to 3 and Comparative Examples 1 to 3, force transmission efficiency, no-load sliding resistance, backlash, buckling load and cutting load were measured. The force transmission efficiency, the no-load sliding resistance, and the backlash were measured using the measuring device shown in FIGS. This is a control cable that has a conduit (1) with a length of 1400 mm on a base (10), bent 180 ° at a radius (R1) of 152.4 mm (6 inches), and then bent at a radius (R2) of 203.2 mm (8 inches). It is fixed by bending it at a right angle. Pulleys (11), (12) and lever (1) are attached to one end (2e) of the inner cable (2).
Connect the reference load (W) etc. via 3),
The other end (2f) is connected with a push-pull force measuring device.

First of all, the force transmission efficiency is measured by applying a pushing and pulling load (W) of 6.8 Kg to one end (2e) of the inner cable (2), and the other end to a push-pull force measuring device (Imada Manufacturing Co. Product name: FB type push-pull scale) was used to perform push-pull operation, and the push-operation force (F1) and the pull-operation force (F2) were measured. As shown in FIG. 17, the load (W) is connected by changing the direction by the pulley (11) during pulling operation, and by the lever (13) and pulley (12) during pushing operation. I struck it with a weight. The described data is the average value of the measured values obtained by pushing and pulling each of the 5 samples about 10 times and then measuring 3 times each. The force transmission efficiency (ηW) was obtained by the formula: (load load (W) operating force (F)) × 100 (%). The results are shown in Table 1.

The no-load sliding resistance is obtained by pushing or pulling the other end (2e) of the inner cable (2) with the push-pull force measuring device in the state shown in FIGS. 16 to 17 with no load (W) attached. The operation was performed, and the pushing operation force and the pulling operation force were measured. After pushing and pulling about 5 times for each of 5 samples, 3
Table 1 shows the average value of the operating force measured each time.

The backlash is measured by fixing the other end (2f) of the inner cable (2) in the device shown in FIGS. 16 to 17 and using the pulleys (11), (12) on the one end (2e) as described above. ) And a lever (13) to apply a push-pull load of 2 kgf and measure the amount of movement at that time.

The length (L1) indicating the fixed position of the inner cable (2) is 20 mm each
The transfer amount was obtained by measuring the reference distance (L2) with a nodule. Table 1 shows the average values of 5 samples measured 3 times each.

The buckling load of the inner cable is measured according to the rod-guide pipe method that is usually used as the end connection method of the push-pull control cable as shown in Fig. 18. A member (16) in which the inner cable (2) is inserted into the pipe (14), one end (2e) of the inner cable (2) is fixed by a chuck (15), and the other end (2f) is seen as a rod. Then, the pressing force that causes the buckling was measured with an Amsler tester.

The grip lengths (C1) and (C2) at both ends of the inner cord (2) are 15 mm and 20 mm, respectively, and the effective length (L5) of the inner cord (2) is
It was set to 75 mm. Table 1 shows the average values measured for three samples.

The cutting load is measured by grasping both ends of the inner cable (2) with a length of 350 mm by 50 mm each (that is, effective length of 250 mm) and gripping it with a chuck of the Amsler tester to pull it, and pulling load when the conduit is cut Was measured. The grips on both ends of the inner cord were pre-wound with a wire and soldered to prevent slipping.

The durability was measured using the device shown in FIG.
One end (2e) of the inner cable (2) is held by a spring (17),
A double swing load (F3) of 0 to 40 kgf was applied to the other end (2f), and the number of times until the inner rope (2) was cut due to bending work was measured.

In FIG. 19, the radius of curvature of the curved portion (R3) was 150 mm, and the total length of the conduit (1) was 850 mm.

As is clear from the results of Table 1, the control cable of the present invention has a clearance of about 1/2 or less as compared with the conventional control cable.
The force transmission efficiency is good, and the no-load sliding resistance is reduced to about 1/2, so it can be seen that there is little friction and high durability. Furthermore, since the clearance is smaller, the backlash is also greatly reduced. Therefore, the transmission of the operating force is reliable and the operability is improved. Moreover, the buckling load and the cutting load are also better than those of the conventional example.

In addition, an inner cord having an outer diameter of 3.5 mm and having a cross-sectional shape shown in FIG. 9 was manufactured as Example 4, and this was inserted into a liner having an inner diameter of 3.7 mm, that is, with a clearance of 0.2 mm, the same as the above method The following data were obtained when the measurement was performed by the method.

Force transmission efficiency Pushing force 74.7% Pulling force 78.2% Unloaded sliding resistance Pushing force 0.3kg Pulling force 0.32kg Backlash 1.7mm Cutting load 1250kgf Durability 1 million times or more This also reduces the clearance between the inner line and the conduit. However, it can be seen that it has higher performance than conventional ones.

EFFECTS OF THE INVENTION Since the push-pull control cable of the present invention has a small clearance, the backlash is small, and therefore, there is little backlash during manual push-pull operation, and the feeling is good. Further, there is an effect that the buckling load is secondarily improved. Even though the clearance is small, the force transmission efficiency is excellent and the durability is not deteriorated.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a control cable of the present invention,
FIG. 2 is an explanatory diagram showing the types of twisting of the strand (4),
3 to 4 are explanatory views showing twisting directions of the inner cord (2), FIGS. 5 to 6 are cross-sectional views and side views of the inner cord (2) related to Example 1, and FIGS. Sectional views of the inner cords (2) related to Examples 2 to 4, respectively, and FIGS. 10 to 11 are sectional views and side views of the inner cords of Comparative Example 1, respectively.
Fig. 13 to Fig. 13 are cross-sectional views and side views of the conventional inner cable as Comparative Example 2, respectively, and Figs. 14 to 15 are cross-sectional views and side views of the conventional inner cable as Comparative Example 3, respectively. Each of the figures is an illustration of the measuring device. (Main symbols in the drawing) (1): Conduit (2): Inner line (3): Core bar (4): Strand (5): Wire

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Open 61-22919 (JP, U) Open 56-39619 (JP, U) Open 53-64755 (JP, U) Open 57- 12740 (JP, Y2) "Kawata Rope for Japanese Industrial Standards" edited by Masakuni Tahara (Sho 52-8-1) Japan Standards Association (P.1-6)

Claims (5)

[Claims] 1. An inner cord inserted into a conduit is such that the direction of the cored bar made of a steel wire having good linearity and the strand of wire appearing on the surface are substantially parallel to the longitudinal direction of the inner cord. A push-pull control cable consisting of a normally twisted strand wound around the core metal. 2. The control cable according to claim 1, wherein the strand is formed by twisting 5 to 22 element wires. 3. The control cable according to claim 1, wherein the steel wire is an oil tempered wire. 4. The control cable according to claim 1 or 2, wherein the steel wire is a brewing wire. 5. The control cable according to claim 1 or 2, wherein the steel wire is a stainless steel wire.