JPH0492111A - Control cable - Google Patents

Abstract

PURPOSE:To enhance durability and load efficiency of a control cable remarkably in the high temperature environment by applying powder paint to the external periphery of an inner rope so that such copolymerized resinous component as four ethylene fluoride perphloro-alkoxyethylene may leave a lay of the inner rope. CONSTITUTION:A inner coat 3 is formed by applying PFA resinous component powder on the external periphery of an inner rope 2 as a coating and baking it. A linear 4 is a material produced by adding elastomer is to PPS resin, and formed on the internal periphery of a conduit 7. A silicone grease lubricant 8 is applied on the external periphery of the inner coat 3. A control cable possesses high durability and good load efficiency in a high temperature environment. High performance durability can be attained under a high temperature environment by using PFA resinous component in the inner coat.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control cable. More specifically, it relates to Control Keple, which has significantly improved durability and load efficiency in high-temperature environments.

[Prior art] Conventionally, in order to improve load efficiency, a plastic coating (hereinafter referred to as the inner coat) was applied to the outer circumference of the inner cable of the control cable, and a plastic tube (hereinafter referred to as the liner) was applied inside the conduit. ) is used in combination with a control pull.

For example, in JP-A-60-231009, the inner coat is made of polytetrafluoroethylene or PTFE.
control cables whose liners are made of polyoxymethylene (hereinafter referred to as POM),
A control cable is shown in which the inner coat is made of nylon 11 and the liner is made of polybutylene terephthalate (hereinafter referred to as PBT). All of these have the effect of reducing wear because the coefficient of friction between the inner coat and the plastic liner is small.

Further, the inner coat at this time is coated with a resin by extrusion molding or the like.

[Problems to be solved by the invention] Recently, however, as machines that use control cables have become more sophisticated and more compact, the load to be borne has increased.
The conditions for their use are becoming increasingly severe, such as rising environmental temperatures and decreasing curvature of the wiring shape.

As a result, the control cable generates more heat during use, causing more friction between the inner coat and liner.
Even the conventional control keple mentioned above does not have sufficient durability or load efficiency. For example, when used at an environmental temperature of 180° C., the control cable of the above combination is not durable and wears out quickly, the inner coat peels off from the inner core, and the inner cable and liner become stuck together, making it inoperable.

In view of the above circumstances, it is an object of the present invention to provide a control cable that has higher durability and load efficiency in high-temperature environments.

[Means for Solving the Problems] The control cable of the present invention includes an inner cable, a conduit through which the inner cable is slidably inserted, and a liner provided between the conduit and the inner cable. A tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin composition is powder coated on the outer periphery of the inner cable so as to leave the strands of the inner cable.

Further, the average particle diameter of the tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin composition is 10 to 50 μm.
It is preferable that the melting index is 1 to 18 g/10 min.

Furthermore, it is preferable that the liner is formed from a polyphenylene sulfide resin composition.

If the average particle diameter of the inner coat resin is less than 10 μm, the particles tend to aggregate, resulting in uneven coating and 50 ALm
If the cable exceeds 100%, the inner cable will not have any strands left as it will become too thick. In addition, the melting index (hereinafter referred to as MFR) is 1
If it exceeds 8 g/10 minutes, it is difficult to obtain a fluid and smooth surface during firing, and if it is less than 1 g/10 minutes, the resin has no fluidity and it is difficult to form a film, resulting in pinholes. The method for measuring MFH is ASTM test method D330.
7-86, measurements were performed at a temperature of 372°C and a load of 5 kg.

Powder coating methods include electrostatic powder spray coating, fluidized dipping, and electrostatic dynamic dipping, in which the inner coat is formed by attaching powder to the inner cable and then baking the resin. .

A tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin composition (hereinafter referred to as
(referred to as PFA resin composition) has an average particle size of 10 to 50
A powder with an MFR of 1 to 18 g/10 min in μm is used,
Preferably, the average particle diameter is 15 to 40 μm and the MFR is 1.
5-18 g/10 min powder is used.

The PFA resin composition may be made of PFA alone, or may include powders such as inorganic fillers (molybdenum disulfide, graphite, etc.), organic fillers (Teflon, polyphenylene sulfide, aromatic polyester, etc.) to improve sliding properties and abrasion resistance. It is also possible to add a small amount of.

The polyphenylene sulfide resin composition (hereinafter referred to as PPS resin composition) that is the material of the liner contains small amounts of PTFE, molybdenum disulfide, graphite, mica, talc, silicone oil, etc. to improve sliding properties and abrasion resistance. It may be added. Additionally, 5% to 40% elastomer was added by weight to improve visibility.
It may be added by weight%.

[Function] The control cable of the present invention has significantly higher durability and good load efficiency in a high temperature environment (180° C.) than conventional control cables.

This performance has been achieved by using a PFA resin composition for the inner coat, achieving high durability in high-temperature environments that is far beyond any conventional control cable.

Conventionally, inner coats such as PBT and nylon 11 coated by extrusion molding have low heat resistance and cannot be used in high-temperature environments18.
When used at 0°C, it wears out quickly, resulting in a decrease in load efficiency. Furthermore, products made by extrusion molding of resins such as PTFE and PFA have good heat resistance and are therefore durable, but the load efficiency after a durability test is reduced. In addition, these inner coats have poor adhesion to the inner cables, so the inner coat wears more on the contact surface with the inner cable strands than on the contact surface with the liner, and when durability tests are continued, the inner coat wears out. It is possible that the inner cord is completely worn away and the inner cord is exposed.

Even with the same PFA resin composition, the adhesion between the inner cable and the inner coat is much better by powder coating the inner cable so that the strands of the inner cable remain, compared to extrusion molding. There is no wear on the contact surface with the strands, and the lubricant is retained in the four parts of the inner coat, so the load efficiency does not decrease even after durability.

In addition, regarding liners, resins such as PBT and ROM have no heat resistance and wear out quickly, resulting in lower load efficiency.If heat-resistant resins such as PTFB are used for liners, they have poor abrasion resistance and wear out. Load efficiency decreases significantly. On the other hand, the liner using the PPS resin composition of the present invention has high heat resistance and good abrasion resistance, so it has high performance durability.

[Example code] Next, the present invention will be explained in detail.

Fig. 1 is a partially cutaway perspective view of an embodiment of the control cable of the present invention, Fig. 2 is a schematic illustration of a measuring device for measuring load efficiency, and Fig. 3 is the measurement results of durability and load efficiency. This is a graph showing.

Referring to FIG. 1, the structure of the control keple of the present invention will be explained.

The control cable (1) of the present invention may have a structure as shown in FIG. 1, but the present invention is not limited to such a structure.

(2) is the inner cable, (3) is the inner coat, (4) is the liner, (5) is the outer spring, (6> is the outer coat, and (7) is the conduit. The inner cable (2) is the steel cable wire 7 It is a wire robe made by twisting books together, and has an outer diameter of 3.0 mm.
It is. The conduit (7) has a rectangular cross section (thickness 1.3 m).
The outer spring (5) is made of steel strips with a width of 2.4 mm and a width of 2.4 mm, wound tightly in a spiral shape to form a tubular shape (outer diameter of 8.6 mm, inner diameter of 6.0 mm), and a thickness of 0.7 mm around its outer periphery. and a synthetic resin outer coat (6) coated with.

Example 1 In the above structure, the inner coat (3) and the liner (
4) is the material shown in Table 1, and the inner coat (3) is the material shown in Table 1.
) is PFA resin composition powder (average particle size: 20 μm
, MFR: 9 g/10 minutes) was coated on the outer periphery of the inner cable (2) and baked at a temperature of 380° C. for 30 minutes, and the outer diameter was 3.2 mm. Also, the liner (4) is P
It is made of a material made by adding 10% by weight of elastomer to PS resin, and the inner circumference of the conduit (7) has an inner diameter of 4.7 mm and an outer diameter of 5.7 m.
It is formed in m.

Furthermore, there is a clearance of 1.5 mm in diameter between the outer circumference of the inner coat (3) and the liner 4), and a lubricant (8) of silicone grease is applied to the outer circumferential surface of the inner coat (3). It is applied at a rate of 4 g/m.

Example 2 A control cable was produced in the same manner as in Example 1, except that the inner coat (3) and liner (4) were made of the materials shown in Table 1.

Comparative Example 1 In the above configuration, the inner coat (3) is made of nylon 6
6 is coated on the outer periphery of the inner cable (2) with a thickness of 0.35 mm by extrusion molding. The liner (4) is made of PBT resin material and is formed on the inner periphery of the conduit (7) with an inner diameter of 4.7 mm and an outer diameter of 5.7 mm.

Furthermore, there is a gap of 1.0 mm in diameter between the outer periphery of the inner coat (3) and the liner (4). , Q mm, and a silicone grease lubricant (8) is applied to the outer peripheral surface of the inner coat (3) at a rate of 0.4 g/m.

Comparative Examples 2 to 3 A control cable similar to Comparative Example 1 was prepared, except that the inner coat (3) and liner (4) were made of the materials shown in Table 1.

Inner coats of Examples 1-2 and Comparative Examples 1-3 (3
) and the materials of the liner (4) are shown in Table 1.

[Margins below] Table 1 Unit of average particle diameter: μm Unit of MFH: g/10 min*: PPS resin with 10% by weight of elastomer added Load efficiency test and durability test were conducted for the above examples and comparative examples did.

The test apparatus will be explained based on FIG. Constant temperature box (11
), the control cable of the co-specimen was attached, which was bent into a semicircle so that the inner cable (2) had a bending radius of 150 mm and a bending angle of 180 degrees. A lever (12) is attached to the input side end of the inner cable (2), and a spring (13) for applying a load is attached to the load side end. Further, a load cell (14) is attached midway on the input side of the inner cable (2), and a load cell (15) is attached midway on the load side. The lever (12) was swung as shown by the arrow (A>) and reciprocated at a speed of 30 times per minute, with each reciprocation being one reciprocation.The spring (13) had a stroke of 30 m.
A load of 70 kgf was applied at m. Constant temperature box (1
1) The temperature inside was maintained at 1.80°C.

Load efficiency is W/FX10 when load side output is 70kgf
It is represented by 0. Note that F) is the input side load cell (1
4), the measured value (W>) is the measured value of the load cell (15) on the load side. The durability was 1 million times.

Figure 3 shows the measurement results of load efficiency and durability.

As is clear from the figure, Comparative Examples 1 and 3 wear quickly and have significantly poor durability, and the load efficiency also quickly decreases.

On the other hand, in Examples 1 and 2 of the present invention, no decrease in load efficiency was observed even after 1 million durability cycles, and a high efficiency of 92 to 93% was maintained. Therefore, it can be seen that the control cable of the present invention has much higher performance than the conventional example in terms of durability and load efficiency in high-temperature environments.

In Comparative Example 2, the liner (4) was the same as that of the present invention, but the inner coat (3) was formed by extrusion molding. In Comparative Examples 1 and 3, both the inner coat (3) and liner (4) were worn out and torn, whereas Comparative Example 2 had durability of 1 million cycles. however,
After 1 million durability cycles, a decrease in load efficiency was observed, and the inner coat (3) was worn at the contact surface with the strands of the inner cable (2).

As long as the control cable of the present invention satisfies the conditions specified in the claims, it can exhibit durability and high load efficiency in high-temperature environments, but the inner coat (3) and liner (4) are made of graphite. It goes without saying that if a lubricant such as PTFE, lubricating oil, etc. is added, the load efficiency will be further improved.

"Effects of the Invention" Compared to conventional cables, the control cable of the present invention has significantly improved durability when used in high-temperature environments, and has high load efficiency.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway oblique view of one embodiment of the control cable of the present invention, Fig. 2 is a schematic explanatory diagram of a measuring device for measuring load efficiency, and Fig. 3 is a measurement of durability and load efficiency. It is a graph showing the results. (Main symbols in the drawing) (1): Control cable (2), inner cable (3): Inner coat (4): Liner (5): Outer spring (6): Outer coat (7), conduit fang 1 Mouth fang 2 Figure 1 Self; Ren (×)

Claims (1)

[Scope of Claims] 1 Consisting of an inner cable, a conduit through which the inner cable is slidably inserted, and a liner provided between the conduit and the inner cable,
A control cable in which the outer periphery of the inner cable is powder-coated with a tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin composition so as to leave the strands of the inner cable. 2. The control cable according to claim 1, wherein the tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin composition has an average particle diameter of 10 to 50 μm and a melting index of 1 to 18 g/10 min. 3. The control cable according to claim 1, wherein the liner is formed from a polyphenylene sulfide resin composition.