JP2012255094A - Grease composition for control cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grease composition which prevents the reduction of load efficiency of a control cable even if the durability number is increased.SOLUTION: The grease composition for a control cable includes: 5-44 mass% of a thickener; 50-89 mass% of a silicone base oil; 1-20 mass% of a powder of a compound having a layer structure; and 5-30 mass% of a polytetrafluoroethylene powder. The silicone base oil has a kinetic viscosity of 50-900 mm/s at 25°C, and contains a low viscosity silicone oil having a kinetic viscosity of 1-300 mm/s at 25°C and a high viscosity silicone oil having a kinetic viscosity of 700-2,000 mm/s at 25°C, wherein the content of the high viscosity silicone oil is 40-90 mass% based on the total mass of the low viscosity silicone oil and the high viscosity silicone oil. The mass ratio between the powder of the compound having a layer structure and the polytetrafluoroethylene powder is 10:90 to 60:40.

Description

  The present invention relates to a grease composition for control cables (hereinafter sometimes simply referred to as “grease composition”).

  The control cable transmits force or movement caused by an operation at the user's hand to a place far away from the user's hand, and is configured such that the inner cable is slidably inserted into the outer casing (Patent Document). 1-3). For example, when the movement of a shift lever of an automobile is transmitted to the transmission via a control cable, when the user operates the shift lever, the inner cable is pushed and pulled, whereby the operation force by the user is transmitted to the transmission.

  In such a control cable, grease is often applied to the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing. As a result, the resistance (sliding resistance) generated when the inner cable slides on the inner peripheral surface of the outer casing is reduced, thereby preventing a reduction in load efficiency.

Japanese Patent Laid-Open No. 07-71434 JP 2000-314416 A JP 2007-321989 A

  However, in the conventional grease, as the number of times the inner cable slides on the inner peripheral surface of the outer casing (hereinafter, sometimes referred to as “durable number”), the lubrication performance may be deteriorated. There is a risk of reducing the load efficiency of the control cable.

  More specifically, this is conspicuous when the inner peripheral surface of the outer casing is formed of polytetrafluoroethylene, but the inner peripheral surface of the outer casing peels off by sliding with the outer peripheral surface of the inner cable, and the wear powder As a result, the lubrication performance of the grease may be reduced, and the load efficiency of the control cable may be reduced. In order to improve this, for example, even if the durability number increases, the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing has sufficient wear resistance, and has low friction and excellent maintenance. It is possible to do.

  The present invention relates to a grease composition for a control cable that can prevent a decrease in load efficiency of the control cable even if the durability number increases.

A grease composition for a control cable according to the present invention includes an inner cable having an outer peripheral surface formed of resin or metal, and an outer casing in which the inner cable can be inserted and an inner peripheral surface is formed of resin. In the cable, it is applied to the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing. Such a grease composition comprises 5 to 44% by weight thickener, 50 to 89% by weight silicone base oil, 1 to 20% by weight compound powder with a layered structure, and 5 to 30% by weight poly Tetrafluoroethylene powder. Silicone base oil, kinematic viscosity at 25 ° C. is 50~900mm ² / s, 25 kinematic viscosity at ° C. is a kinematic viscosity at a 25 ° C. Low viscosity silicone oil 1~300mm ² / s 700~2000mm ² / s The high-viscosity silicone oil is 40 to 90% by mass based on the total mass of the low-viscosity silicone oil and the high-viscosity silicone oil. The mass ratio of the compound powder having a layered structure and the polytetrafluoroethylene powder is 10:90 to 60:40.

The application amount of the grease composition per unit area of the outer peripheral surface of the inner cable is preferably 45 g / m ² or more and 220 g / m ² or less.

  The grease composition according to the present invention is preferably used for a control cable in which the inner peripheral surface of the outer casing is formed of polytetrafluoroethylene.

  The compound powder having a layered structure is, for example, at least one of graphite powder and boron nitride powder.

The thickener is, for example, a scaly lithium-based thickener.
The control cable according to the present invention is formed by applying the grease composition to the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing.

  With the grease composition for a control cable according to the present invention, it is possible to prevent a decrease in load efficiency of the control cable even if the durability number is increased.

It is a cross-sectional view of a control cable according to an embodiment of the present invention. It is a cross-sectional view of a control cable according to another embodiment of the present invention. It is a schematic plan view of the apparatus used for an endurance test. It is a graph which shows the result of the endurance test in an example. It is a graph which shows the result of the endurance test in another example.

<Grease composition>
The grease composition according to the present invention will be described. In addition, the grease composition which concerns on this invention is not limited to the matter shown below.

  The grease composition according to the present invention is used for a control cable. In the control cable, the inner cable is inserted into the outer casing, and the grease composition according to the present invention is applied to the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing. Such a grease composition comprises 5 to 44% by weight thickener, 50 to 89% by weight silicone base oil, 1 to 20% by weight compound powder with a layered structure, and 5 to 30% by weight poly Tetrafluoroethylene powder (hereinafter sometimes referred to as “PTFE powder”. PTFE is an abbreviation for polytetrafluoroethylene).

<Thickener>
The material of the thickener is not particularly limited. The thickener in the present invention may be any material that is usually used as a grease thickener, and specifically, any metal soap-based thickener, composite metal soap-based thickener, polyurea, or the like. Preferably, it is a lithium soap thickener.

  Examples of the lithium soap thickener include aliphatic carboxylic acid lithium salts having a hydroxyl group such as lithium-12-hydroxystearate, aliphatic carboxylic acid lithium salts such as lithium stearate, and mixtures thereof. Among these, from the viewpoint of durability of the grease composition, the lithium soap thickener is preferably lithium stearate.

  A lithium soap-based thickener is usually prepared by blending lithium soap of scale-like particles in a solvent composed of a base oil, heating it to around 200 ° C. to dissolve the lithium soap in the base oil, and then cooling to crystallize it. By making it crystallize (so-called recrystallization), the lithium soap thickener itself is produced in a fibrous form. However, in the present invention, the frictional force generated when the inner cable slides on the inner peripheral surface of the outer casing (hereinafter sometimes referred to as “when the inner cable slides”) is reduced, resulting in load efficiency. From the viewpoint of suppressing the decrease in the viscosity, it is preferable to use a lithium soap-based thickener of scaly particles dispersed in a base oil at around 90 to 150 ° C. instead of a fibrous lithium soap-based thickener. The temperature for stirring and dispersing lithium soap of scale-like particles in the base oil is preferably 90 to 150 ° C, more preferably 90 to 140 ° C, and further preferably 95 to 130 ° C. If this temperature is less than 90 degreeC, it exists in the tendency for the dispersibility to the base oil of scale-like particles of lithium soap to fall. Moreover, when this temperature exceeds 150 degreeC, some lithium soaps of scale-like particle | grains may become fibrous form, and the lithium soap type | system | group thickener of scale-like particle | grains may not be obtained.

  The content of the thickener in the grease composition is 5 to 44% by mass, preferably 10 to 40% by mass. If the content of the thickener is less than 5% by mass, the frictional force generated when the inner cable slides increases, and as a result, the load efficiency tends to decrease. On the other hand, when the content of the thickener exceeds 44% by mass, the life of the grease composition tends to be shortened.

<Silicone base oil>
The silicone base oil has a kinematic viscosity at 25 ° C. of 50 to 900 mm ² / s. The kinematic viscosity of the silicone base oil at 25 ° C. is preferably 100 to 850 mm ² / s, more preferably 200 to 600 mm ² / s. If the kinematic viscosity of the silicone base oil at 25 ° C. is less than 50 mm ² / s, the formation of an oil film on the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing is not sufficient. The wear resistance of the inner peripheral surface of the steel tends to decrease, and as a result, the load efficiency tends to decrease. On the other hand, if the kinematic viscosity of the silicone base oil at 25 ° C. exceeds 900 mm ² / s, the amount of the grease composition entering between the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing tends to decrease. As a result, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing decreases, and as a result, the load efficiency tends to decrease. The kinematic viscosity is measured according to JIS K 2283 (crude oil and petroleum products—kinematic viscosity test method) using, for example, a glass capillary viscometer.

The silicone base oil in the present invention is a mixture of the following low viscosity silicone oil and the following high viscosity silicone oil so that the kinematic viscosity at 25 ° C. is 50 to 900 mm ² / s. Any silicone or various modified silicones may be used, and dimethyl silicone is preferable. However, these silicones may be mixed.

The low viscosity silicone oil is a silicone oil having a kinematic viscosity at 25 ° C. of 1 to 300 mm ² / s, preferably a silicone oil having a kinematic viscosity at 25 ° C. of 5 to 250 mm ² / s, more preferably 20 to 180 mm. ² / s silicone oil. If the kinematic viscosity of the low-viscosity silicone oil at 25 ° C. is less than 1 mm ² / s, the oil film is not sufficiently formed on the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing. There is a tendency that the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing is worn (hereinafter, simply described as “the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing is reduced”). On the other hand, when the kinematic viscosity of the low-viscosity silicone oil at 25 ° C. exceeds 300 mm ² / s, the amount of the grease composition entering between the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing tends to decrease. Therefore, as a result, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends to decrease.

  10-60 mass% of low-viscosity silicone oil is contained with respect to the total amount of low-viscosity silicone oil and high-viscosity silicone oil, Preferably it is contained 20-50 mass%. When the content of the low-viscosity silicone oil is out of this range, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends to be insufficient.

The high-viscosity silicone oil is a silicone oil having a kinematic viscosity at 25 ° C. of 700 to 2,000 mm ² / s, preferably 700 to 1500 mm ² / s. If the range of the kinematic viscosity of the high-viscosity silicone oil at 25 ° C. is out of this range, it is difficult to adjust the kinematic viscosity of the silicone base oil at 25 ° C. to 50 to 900 mm ² / s by mixing with the low-viscosity silicone oil. Become.

  The high-viscosity silicone oil is contained in an amount of 40 to 90% by mass, preferably 50 to 80% by mass, based on the total mass of the low-viscosity silicone oil and the high-viscosity silicone oil. When the content of the high-viscosity silicone oil is out of this range, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends to be insufficient.

  Content of the silicone base oil in a grease composition is 50-89 mass%, Preferably, it is 60-85 mass%. When the content of the silicone base oil is less than 50% by mass, the solid content of the solid lubricant increases, and the grease composition tends to solidify. On the other hand, when the content of the silicone base oil exceeds 89% by mass, the solid content of the solid lubricant is reduced, and the durability and lubricity of the grease composition tend to be lowered.

  The grease composition according to the present invention may contain a base oil other than the silicone base oil, but the amount of the base oil other than the silicone base oil should be suppressed to 5% by mass or less based on the silicone base oil. Is preferred.

<Compound powder with layered structure>
The compound powder having a layered structure is a powder of a compound having a layered crystal structure. For example, molybdenum disulfide, tungsten disulfide, graphite, graphite fluoride, mica, MCA (abbreviation of Melamine Cyanurate Acid), boron nitride, or transition It is a powder of an incalation compound such as metal dichalcogenide. The compound powder having a layered structure is preferably a powder of mica, graphite, boron nitride, MCA, or molybdenum disulfide, and more preferably a powder of graphite or boron nitride. The grease composition according to the present invention may include a powder of one kind of the above materials as a compound powder having a layered structure, or a powder of two or more kinds of the above materials having a layered structure. It may be included as a compound powder.

  Graphite is roughly classified into artificial graphite and natural graphite. Artificial graphite is produced by solidifying pitch coke with tar or pitch, firing it at about 1200 ° C., and then processing it at a high temperature in a graphite furnace to grow carbon crystals. Natural graphite is obtained by graphitizing a carbon component of a plant or the like with a long period of time due to natural geothermal heat and underground high pressure. The graphite powder used in the present invention is preferably natural graphite powder. Examples of the natural graphite powder include scaly graphite powder, scaly graphite powder, and earthy graphite powder, depending on the material used, and scaly graphite powder or scaly graphite powder is preferred.

  Regarding the average particle size of the compound powder having a layered structure, the volume average particle size of the compound powder having a layered structure measured by a laser diffraction scattering method is preferably 0.1 to 25 μm, more preferably 2.1 to 20 μm. More preferably, it is 2.2-15 micrometers. Even if the volume average particle diameter of the layered compound powder is less than 0.1 μm and the volume average particle diameter of the layered compound powder exceeds 25 μm, the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing There is a tendency for the wear resistance of the steel to decrease. In addition, the average particle diameter of the compound powder having a layered structure can be measured according to a method such as a dynamic light scattering method or a Coulter method in addition to the laser diffraction scattering method.

  When the compound powder having a layered structure is a graphite powder, the average particle diameter is preferably 1 to 15 μm, more preferably 2.1 to 10 μm. Even if the average particle size of the graphite powder is less than 1 μm and the average particle size of the graphite powder exceeds 15 μm, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends to decrease. . In particular, when the compound powder having a layered structure is flaky graphite powder or scaly graphite powder, the average particle diameter is preferably 2.1 to 10 μm, more preferably 2.1 to 8 μm.

  When the compound powder having a layered structure is boron nitride powder, the average particle diameter is preferably 0.5 to 20 μm, more preferably 0.5 to 10 μm, and further preferably 1 to 5 μm. Even if the average particle size of the boron nitride powder is less than 0.5 μm and the average particle size of the boron nitride powder exceeds 20 μm, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing is reduced. Tend to.

  The lower limit of the content of the layered structure compound powder in the grease composition is 1% by mass, preferably 3% by mass, and more preferably 5% by mass. The upper limit of the content of the compound powder having a layered structure in the grease composition is 20% by mass, preferably 15% by mass, and more preferably 10% by mass. If the content of the compound powder having a layered structure in the grease composition is less than 1% by mass, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends to decrease. Even if the content of the compound powder having a layered structure in the grease composition exceeds 20% by mass, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends not to be further improved.

<PTFE powder>
PTFE has a band-like structure as a whole, and the band has a band structure in which plate-like crystal portions and amorphous portions are alternately arranged in a sandwich shape.

  Regarding the average particle diameter of the PTFE powder, the volume average particle diameter of the PTFE powder measured by a laser diffraction scattering method is preferably 0.1 to 25 μm, more preferably 0.5 to 15 μm, and even more preferably 1. 0.0 to 10 μm. Even if the volume average particle size of the PTFE powder is less than 0.1 μm or the volume average particle size of the PTFE powder exceeds 25 μm, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing is reduced. Tend to. The average particle size of the PTFE powder can be measured according to a method such as a dynamic light scattering method or a Coulter method in addition to the laser diffraction scattering method.

  The lower limit of the content of PTFE powder in the grease composition is 5% by mass, preferably 7% by mass, and more preferably 14% by mass. The upper limit of the content of PTFE powder in the grease composition is 30% by mass, preferably 25% by mass, and more preferably 20% by mass. If the content of PTFE powder in the grease composition is less than 5% by mass, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends to decrease. Even if the content of the PTFE powder in the grease composition exceeds 30% by mass, the wear resistance of the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing tends not to be improved.

<Mass ratio of compound powder of layered structure and PTFE powder>
The mass ratio of the compound powder having a layered structure and the PTFE powder is 10:90 to 60:40, preferably 20:80 to 50:50, and more preferably 20:80 to 40:60.

  When the blending ratio of the compound powder of the layered structure (= (mass of compound powder of the layered structure) ÷ (total mass of compound powder of the layered structure and PTFE powder) × 100) is less than 10%, the outer peripheral surface of the inner cable and When at least one surface of the inner peripheral surface of the outer casing is made of PTFE resin or high-density PE (polyethylene) resin, the wear resistance of the surface tends to decrease. The same can be said when the blending ratio of the PTFE powder exceeds 90%.

  On the other hand, if the compounding ratio of the compound powder having a layered structure exceeds 60%, at least one of the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing is made of PBT (polybutylene terephtalate) resin when sliding. There is a tendency that the frictional force generated in the case increases. The same can be said when the blending ratio of the PTFE powder is less than 40%.

  However, if the mass ratio of the compound powder having a layered structure and the polytetrafluoroethylene powder is 10:90 to 60:40, the inner cable does not depend on the materials of the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing. In the outer peripheral surface of the outer casing or the inner peripheral surface of the outer casing, it is possible to prevent a decrease in wear resistance, and it is possible to prevent an increase in frictional force generated on the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing when the inner cable slides.

<Other additives>
The grease composition according to the present invention may further contain one or more of the additives listed below. The additive may be, for example, a metal detergent such as alkaline earth metal sulfonate, alkaline earth metal phenate, or alkaline earth metal salicylate, or an alkenyl succinimide, an alkenyl succinimide boronated modified product. , A dispersant such as benzylamine or alkylpolyamine, or various antiwear agents such as zinc, sulfur, phosphorus, amine or ester, polymethacrylate, Various viscosity index improvers such as ethylene propylene copolymer, styrene-isoprene copolymer, hydride of styrene-isoprene copolymer, or polyisobutylene may be used, and 2,6-di-tert-butyl- alkylphenols such as p-cresol, 4,4′-methylenebis- (2,6-di-tert-butyl) Bisphenols such as tilphenol), phenolic compounds such as n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-tert-butylphenol) propionate, or aromatics such as naphthylamines or dialkyldiphenylamines Various antioxidants such as amine compounds may be used, and extreme pressure agents such as sulfurized olefins, sulfurized fats and oils, methyltrichlorostearate, chlorinated naphthalene, iodinated benzyl, fluoroalkylpolysiloxane, or lead naphthenate. Alternatively, various rust inhibitors such as carboxylic acid such as stearic acid, dicarboxylic acid, metal soap, carboxylic acid amine salt, heavy sulfonic acid metal salt, or carboxylic acid partial ester of polyhydric alcohol may be used. Benzotriazole or benzimi It may be a variety of corrosion inhibitors such as tetrazole.

<Grease composition application amount>
The coating amount of the grease composition per unit area on the outer peripheral surface of the inner cable is preferably 45 g / m ² or more and 220 g / m ² or less, more preferably 45 g / m ² or more and 210 g / m ² or less. If the application amount of the grease composition is less than 45 g / m ² , an oil film is not sufficiently formed on the outer peripheral surface of the inner cable or the inner peripheral surface of the outer casing. The wear resistance of the peripheral surface tends to decrease. In addition, grease tends to run out and lubrication performance cannot be obtained. On the other hand, when the application amount of the grease composition exceeds 220 g / m ² , sliding between the inner cable and the outer casing is hindered, and normal lubricating performance tends to be not obtained.

  Here, the “outer peripheral surface of the inner cable” serving as a reference for the application amount of the grease composition will be described. When the inner cable is composed of two layers of the shaft and the strand (shown in FIG. 1 described later), the outer peripheral surface of the inner cable is a virtual contact with the outermost strand portion in the radial direction of the inner cable. It becomes a rough surface. When the inner cable is composed of three layers of a shaft, a strand, and a coat layer (shown in FIG. 2 described later), the outer peripheral surface of the inner cable is the outer peripheral surface of the coat layer.

<Method for producing grease composition>
In the grease composition according to the present invention, the thickener, the silicone base oil, the compound powder having the layered structure, and the PTFE powder are mixed in predetermined amounts, and at least one of the additives is added as necessary. It is manufactured.

<Control cable>
The control cable according to the present invention is configured such that the inner cable is inserted into the outer casing, and the grease composition according to the present invention is applied to the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing. The outer peripheral surface of the inner cable is formed of resin or metal, and the inner peripheral surface of the outer casing is formed of resin.

  In this invention, it is not limited to each structure of an inner cable and an outer casing. Below, the outline of each structure of an inner cable and an outer casing is shown.

  The inner cable may be composed of two layers of a shaft and a strand, or may be composed of three layers of a shaft, a strand, and a coat layer. The shaft is preferably made of a material having moderate rigidity and toughness, such as a carbon steel wire or carbon fiber. The strand is arranged on the outer peripheral surface of the shaft and twisted in a predetermined direction, and may be made of a material having a toughness while having an appropriate rigidity like the shaft. The coat layer covers the strand and may be made of a material having an appropriate rigidity like the shaft, or may be made of a resin such as PA (polyamide) 66.

  The outer casing is preferably composed of three layers of a liner through which the inner cable is inserted, a shield, and a coat layer. The liner may be made of a resin, and is preferably made of a PTFE resin. Thereby, the effect that sliding performance with an inner cable improves is acquired. The shield may be disposed on the outer peripheral surface of the liner and twisted in a predetermined direction, and may be made of a material having an appropriate rigidity and a toughness like the shaft of the inner cable. The coat layer covers the shield and may be made of a resin such as PP (polypropylene) resin or polyester elastomer (hereinafter referred to as “TPC”).

Examples of the present invention will be described below. In addition, this invention is not limited to the Example shown below.
<Example 1>
<Preparation of grease composition>
Lithium stearate A, a silicone base oil composed of silicone oil A and silicone oil C, boron nitride, PTFE powder, and an antioxidant were charged into a heat-resistant container. The blending amounts at this time are as shown in Table 1. Thereafter, the mixture was sufficiently stirred at about 100 ° C. to disperse lithium stearate A and milled. As a result, a grease composition (grease composition of Example 1) in which scaly lithium-stearate particles were dispersed in a silicone base oil was obtained.

<Production of control cable>
The control cable 10 shown in FIG. 1 was produced using the obtained grease composition. FIG. 1 is a schematic diagram illustrating a cross section of a control cable 10 according to the first embodiment.

  Specifically, an inner cable 20 and an outer casing 30 constituting the control cable 10 were prepared. The inner cable 20 includes a shaft 21 and nine strands 23, and the strands 23 are arranged on the outer peripheral surface of the shaft 21 and are twisted in the S direction. Each strand 23 includes a strand core wire 25 and six strand side wires 27. The strand side wires 27 are arranged on the outer peripheral surface of the strand core wire 25 and are twisted in the Z direction.

  The shaft 21 was made of a wire obtained by subjecting a carbon steel wire defined by SWRH72A of JIS G 3506 to an oil temper treatment. The strand core wire 25 and the strand side wire 27 were each made of a wire material that was subjected to wire drawing after galvanizing a carbon steel wire material defined by SWRH62A of JIS G 3506.

  The outer diameter of the inner cable 20 is 2.92 mm, the outer diameter of the shaft 21 is 1.6 mm, the outer diameter of the strand core wire 25 is 0.265 mm, and the outer diameter of the strand side wire 27 is 0.24 mm. It was.

  The outer casing 30 is composed of a liner 31 through which the inner cable 20 is inserted, 20 shields 33, and a coat layer 35. The shield 33 was disposed on the outer peripheral surface of the liner 31 and twisted in the Z direction, and was covered with the coat layer 35.

  The liner 31 is made of PTFE resin (product name “Hi-Flon” manufactured by Nissei Electric Co., Ltd.), and the shield 33 is made of a carbon steel wire defined by SWRH62A of JIS G 3506, which is galvanized and coated. The layer 35 was made of PP resin (product name “ZELATH” manufactured by Mitsubishi Chemical Corporation).

  The outer diameter of the outer casing 30 was 8.2 mm, the inner diameter of the liner 31 was 3.2 mm, the outer diameter of the liner 31 was 4.5 mm, and the outer diameter of the shield 33 was 0.8 mm.

  And it apply | coated to the outer peripheral surface of the inner cable 20 so that the application quantity of a grease composition might become the value of Table 1, and the inner cable 20 was penetrated to the liner 31 of the outer casing 30. FIG. Thus, the control cable 10 of Example 1 was obtained.

<Durability test>
A durability test was performed on the obtained control cable 10. FIG. 3 is a schematic plan view of an apparatus used for the durability test.

  Specifically, the control cable 10 was routed in the shape described in “Wiring” in Table 4 and placed in the thermostatic chamber 91. After that, a spring 95 is connected to one end of the inner cable 20 to give a test load W, and the other end of the inner cable 20 is reciprocated at a speed of 30 cpm (cycle / min) and a stroke length of 30 mm by a push / pull force measuring instrument 93. The load F (tensile force) was measured. Then, the load efficiency for each number of reciprocations (endurance number) was calculated by (load efficiency (%)) = (test load W) ÷ (operation load F) × 100. This test was performed by changing the temperature of the thermostatic chamber 91 to −40 ° C., 20 ° C., and 120 ° C.

<Examples 2-4, Comparative Examples 1-3>
Examples 2 to 4 and Comparative Examples 1 to 3 were the same as Example 1 except that the amount of the material constituting the grease composition was changed to the values shown in Table 1.

<Examples 5-8, Comparative Examples 4-7>
In Examples 5 to 8 and Comparative Examples 4 to 7, the control cable 50 shown in FIG. 2 was prepared according to the method shown below in which the blending amount of the material constituting the grease composition was changed to the values shown in Table 2. Except this, it was the same as Example 1 above.

  In addition, also in Examples 5-8 and Comparative Examples 4-7, the durability test with respect to the control cable 50 was done using the apparatus shown in FIG.

<Production of control cable>
The control cable 50 shown in FIG. 2 was produced using the obtained grease composition. FIG. 2 is a schematic diagram illustrating a cross section of the control cable 50 according to the fifth embodiment.

  Specifically, an inner cable 60 and an outer casing 70 constituting the control cable 50 were prepared. The inner cable 60 was composed of a shaft 61, a strand 63, and a coat layer 69. In the strand 63, six strand core wires 65 are arranged on the outer peripheral surface of the shaft 61 and twisted in the Z direction, and the six first strand side wires 67A and the six second strand side wires 67B are surrounded. It was arranged on the outside of the strand core wire 65 so as to alternate in the direction, and was twisted in the S direction. The strand 63 thus configured was covered with the coat layer 69.

  The shaft 61, the strand core wire 65, the first strand side wire 67 </ b> A, and the second strand side wire 67 </ b> B were made of a wire material obtained by subjecting a carbon steel wire material defined by SWRH72A of JIS G 3506 to an oil temper treatment. The coat layer 69 was made of PA66 resin (product name “Leona” manufactured by Asahi Kasei Chemicals Corporation).

  The outer diameter of the inner cable 60 is 4.3 mm, the outer diameter of the shaft 61 is 0.65 mm, the outer diameter of the strand core wire 65 is 0.6 mm, and the outer diameter of the first strand side wire 67A is 0.00 mm. The outer diameter of the second strand side line 67B was 0.5 mm.

  The outer casing 70 includes a liner 71 through which the inner cable 60 is inserted, 24 shields 73, and a coat layer 75, and has substantially the same configuration as the outer casing 30 in FIG.

  The liner 71 is made of PTFE resin (product name “Hi-Flon” manufactured by Nissei Electric Co., Ltd.), and the shield 73 is made of a carbon steel wire defined by SWRH62A of JIS G 3506, which is galvanized. The coat layer 75 was made of TPC (product name “Perprene” manufactured by Toyobo Co., Ltd.).

  The outer diameter of the outer casing 70 was 9.0 mm, the inner diameter of the liner 71 was 4.65 mm, the outer diameter was 6.0 mm, and the outer diameter of the shield 73 was 0.884 mm. Thereafter, a control cable 50 was obtained according to the same method as in Example 1.

<Examples 9 to 11 and Comparative Examples 8 to 9>
In Example 9, Example 11, and Comparative Examples 8-9, it was the same as that of the said Example 1 except having changed the compounding quantity of the material which comprises a grease composition into the value shown in Table 3.

  Example 10 was the same as Example 1 except for the method for preparing the grease composition. Specifically, lithium stearate B and silicone base oil were put into a heat-resistant container and heated while stirring to dissolve lithium stearate B at about 200 ° C. Then it was cooled. Next, boron nitride, PTFE powder, and an antioxidant were further added to a heat-resistant container, and the mixture was sufficiently stirred at about 100 ° C. to perform a mill treatment. As a result, a grease composition (grease composition of Example 10) in which fibrous lithium-stearate crystals were dispersed in a silicone base oil was obtained.

  The results are shown in Tables 1 to 3 and FIGS. 4A to 4C are graphs showing the results of Example 3 and Comparative Example 1 when the temperature of the thermostatic chamber 91 is −40 ° C., 20 ° C., and 120 ° C., respectively. 5A to 5C are graphs showing the results of Example 7 and Comparative Example 4 when the temperature of the thermostatic chamber 91 is −40 ° C., 20 ° C., and 120 ° C., respectively.

The annotations in Tables 1-3 are as follows.
(Note 1) Lithium stearate A: S7000H manufactured by Sakai Chemical Industry Co., Ltd.
(Note 2) Lithium stearate B: S7000 manufactured by Sakai Chemical Industry Co., Ltd.
(Note 3) Silicone oil A: Dimethyl silicone oil with a kinematic viscosity at 25 ° C. of 50 mm ² / s (Note 4) Silicone oil B: Dimethyl silicone oil with a kinematic viscosity at 25 ° C. of 200 mm ² / s (Note 5) Silicone oil C: Dimethyl silicone oil with a kinematic viscosity at 25 ° C. of 1000 mm ² / s (Note 6) Silicone oil D: Dimethyl silicone oil with a kinematic viscosity at 25 ° C. of 500 mm ² / s (Note 7) Graphite: scale powder, average particle size 5 μm
(Note 8) Boron nitride: powder, average particle size 1.5 μm
(Note 9) PTFE: powder, average particle size 4.0 μm
(Note 10) Antioxidant: Amine-based antioxidant (Note 11) The load efficiency value before the endurance test is indicated on the front, and the load efficiency value after the endurance number of 2 million times is indicated on the rear. (Note 12) The value of load efficiency before the endurance test is written in the front, and the value of load efficiency after the endurance number is 1 million times is written in the rear.

  The kinematic viscosity at 25 ° C. was measured using a glass capillary viscometer according to JIS K 2283 (crude oil and petroleum products—kinematic viscosity test method).

The annotations in Table 4 are as follows.
(Note 13) R150 × 180 °: The control cable 10 is routed so that the bending radius R is 150 mm and the total bending angle is 180 degrees. Here, the bending radius R is “R” shown in FIG. 3. (Note 14) R100 × 180 °: The control cable 50 is routed so that the bending radius R is 100 mm and the total bending angle is 180 degrees.

  In Table 4, “inner cable length I”, “outer casing length L”, and “test load W” are “I”, “L”, and “W” shown in FIG. 3, respectively.

<Evaluation results>
In Examples 1 to 4, as compared with Comparative Example 1, a decrease in load efficiency of the control cable accompanying an increase in the durability number was prevented. This effect was remarkable in the durability test at −40 ° C. and 20 ° C. The reason is that in Examples 1 to 4, since the low viscosity silicone oil is contained in the silicone base oil, the grease composition easily enters between the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing. Therefore, it is considered that the wear of the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing is suppressed. In addition, in Examples 1 to 4, since the grease composition contains a layered compound (boron nitride), wear on the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing is suppressed, and the inner This is because the friction generated on these surfaces during the sliding of the cable is reduced.

  Moreover, in Examples 1-4, the fall of the load efficiency of the control cable accompanying the increase in the durable number was prevented compared with Comparative Examples 2-3. In Comparative Example 2 and Comparative Example 3, the load efficiency of the control cable accompanying the increase in the durability number was lower in Comparative Example 3 than in Comparative Example 2. The reason for this is that in Examples 1 to 4, the content of the high-viscosity silicone oil in the silicone base oil is 40% by mass or more and 90% by mass or less, and therefore a predetermined amount of low-viscosity silicone oil is included in the silicone base oil. Therefore, it is considered that the wear of the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing is suppressed.

  In Examples 5 to 8, as compared with Comparative Examples 4 to 7, a decrease in load efficiency of the control cable accompanying an increase in the durability number was prevented. As the reason, the same reason as in Examples 1 to 4 can be considered.

  Moreover, in Examples 5-8, the fall of the load efficiency of the control cable accompanying the increase in the durable number was prevented not only in the durability test at -40 degreeC and 20 degreeC but in the durability test at 120 degreeC. The reason is considered that the outer peripheral surface of the inner cable is made of resin, so that the sliding performance with the outer casing is good and the wear is reduced.

  In Examples 9 to 10, as compared with Comparative Example 8, a decrease in load efficiency of the control cable accompanying an increase in the durability number was prevented. The reason is considered to be that in Examples 9 to 10, the application amount of the grease composition is optimized.

  Further, in Example 10, as in Example 9, a decrease in load efficiency of the control cable accompanying an increase in the durability number was prevented. Therefore, it is considered that the effect of preventing the load efficiency of the control cable from being lowered due to the increase in the durability number can be obtained without being limited to the thickener material.

In Example 11, the load efficiency of the control cable accompanying the increase in the durability number was slightly lower than that in Examples 9 and 10, but higher than that in Comparative Example 9, and the function of the control cable was maintained. Therefore, it is considered that the application amount of the grease composition is preferably 220 g / m ² or less.

  In addition, even when graphite is used for the compound powder having a layered structure, it is considered that the load efficiency of the control cable is prevented from decreasing due to the increase in the durability number, as in Examples 9 to 10.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10 control cable, 20 inner cable, 21 shaft, 23 strand, 25 strand core wire, 27 strand side wire, 30 outer casing, 31 liner, 33 shield, 35 coat layer, 50 control cable, 60 inner cable, 61 shaft, 63 strand, 65 strand core wire, 67A first strand side wire, 67B second strand side wire, 69 coat layer, 70 outer casing, 71 liner, 73 shield, 75 coat layer.

Claims (6)

A control cable comprising an inner cable having an outer peripheral surface formed of resin or metal, and an outer casing in which the inner cable can be inserted, and an inner peripheral surface formed of resin, the outer peripheral surface of the inner cable and A grease composition for a control cable applied to the inner peripheral surface of the outer casing,
5 to 44% by weight thickener;
50-89 mass% silicone base oil;
1 to 20% by mass of a compound powder having a layered structure;
5-30 mass% polytetrafluoroethylene powder,
The silicone base oil is
The kinematic viscosity at 25 ° C. is 50 to 900 mm ² / s,
Includes a low viscosity silicone oil having kinematic viscosity of 1 to 300 mm ² / s, and a high viscosity silicone oil kinematic viscosity of 700~2000mm ² / s at 25 ° C. at 25 ° C.,
The content of the high viscosity silicone oil is 40 to 90% by mass with respect to the total mass of the low viscosity silicone oil and the high viscosity silicone oil,
A grease composition for a control cable, wherein a mass ratio of the compound powder having a layered structure and the polytetrafluoroethylene powder is 10:90 to 60:40. 2. The grease composition for a control cable according to claim 1, wherein an application amount of the grease composition for a control cable per unit area of the outer peripheral surface of the inner cable is 45 g / m ² or more and 220 g / m ² or less.   The grease composition for a control cable according to claim 1 or 2, which is used for a control cable in which the inner peripheral surface of the outer casing is formed of polytetrafluoroethylene.   The grease composition for a control cable according to any one of claims 1 to 3, wherein the compound powder having a layered structure is at least one of graphite powder and boron nitride powder.   The grease composition for a control cable according to any one of claims 1 to 4, wherein the thickener is a flaky lithium soap thickener.   A control cable obtained by applying the grease composition for a control cable according to any one of claims 1 to 5 to the outer peripheral surface of the inner cable and the inner peripheral surface of the outer casing.

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