JP4303800B2 - Push-pull control cable for automobile transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a push / pull control cable for an automobile transmission that is operated by a push-pull operation.
[0002]
[Prior art]
The control cable that connects the transmission and the shift lever of an automobile is formed by covering the outer periphery of a liner made of a resin pipe with a strand wound with a fine metal wire and covering the outer periphery of the strand with a waterproof jacket. A push-pull control cable having a conduit and a wire composed of a side wire in which a large number of small steel wires are wound around the outer periphery of a core wire is used. The side lines of the wire are subjected to a surface treatment such as galvanization in order to improve rust prevention and slidability between the liner and the wire.
[0003]
Conventionally, sufficient consideration has not been given to the durability of the surface treatment layer such as plating applied to the side wires, and the thickness of the surface treatment layer such as galvanization has been about 1 to 3 μm. For this reason, in the long-term use, a part of the surface treatment layer is peeled off by sliding with the liner to expose the bare metal and increase the friction coefficient. An increase in the coefficient of friction results in a decrease in load efficiency indicating the ratio of the output load to the input load, thereby reducing the sensibility quality and operability. As a result, the push / pull control cable needs to be replaced.
[0004]
[Problems to be solved by the invention]
In recent years, in the durable consumer goods such as automobiles, and the maintenance of quality-sensitive and operation of high long-term, maintenance-free and there is a demand that cotton in long-term close to the shelf life.
An object of the present invention is to provide a push-pull control cable for an automobile transmission that can maintain high quality sensibility and operability over a long period of time and is maintenance-free.
[0005]
[Means for Solving the Problems]
The present invention relates to an automobile transmission comprising a conduit having a liner made of a resin pipe, and a wire formed by screwing a small-diameter side wire around the outer periphery of a core wire and slidably inserted into the liner. In the push-pull control cable, the core wire is a steel wire having a diameter of 1.2 mm or more and 1.6 mm or less, and the side wire is wound once around the outer periphery of the core wire at a predetermined pitch so that the diameter is 0.1 mm. It consists of a group of steel wires with a thickness of 25 mm or more and 0.6 mm or less, and the side wires are galvanized with a thickness of 5 μm or more and 20 μm or less to make the surface roughness 0.2 μm or less in terms of Ra, and with a load of 200 N It is characterized by being able to ensure a load efficiency of 70% or more after 1 million repeated durability tests with a stroke of ± 30 mm .
[0006]
[Operation and effect of the invention]
In the wire according to the present invention, the side wire is galvanized with a thickness of 5 μm or more and 20 μm or less and the surface roughness is 0.2 μm or less in terms of Ra, so that high quality sensibility and operability are maintained over a long period of time. For this reason, when using it for the control cable which connects the transmission of a motor vehicle, and a shift lever, exchange becomes unnecessary practically. As a result, it is possible to reduce labor and cost for maintenance of automobiles. The conduit is formed by covering the outer periphery of the liner with a thin strand of fine metal wire, and covering the outer periphery of the strand with a waterproof jacket . The word tire lateral line, diameter of 1.2mm or more, a number of steel wire on the outer circumference of the following core 1.6 mm (diameter 0.25mm or more, 0.6 mm or less) were Nishimaki a singlet at a predetermined pitch The structure is advantageous in securing rigidity and reducing costs.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a push / pull control cable 1 (hereinafter simply referred to as a push / pull control cable 1) for an automobile transmission according to the present invention. The push-pull control cable 1 includes a conduit 2 having a liner 21 made of a polybutylene terephthalate pipe, and a side wire 33 formed by winding a large number of small-diameter steel wires 32 around the core wire 31. The wire 3 is slidably inserted into the liner 21 with a predetermined gap, and connects the automobile transmission and the shift lever.
[0008]
The conduit 2 includes a strand 22 in which a steel wire group having a diameter of 0.83 mm is wound around the outer periphery of the liner 21 and a waterproof jacket 23 that covers the outer periphery of the strand 22. The liner 21 can also use a fluororesin, a polyolefin resin, or a polyether resin.
[0009]
The wire 3 has a structure in which a steel wire having a diameter of 1.4 mm is used for the core wire 31 and the steel wire 32 has a diameter of 0.3 mm and is wound around the outer periphery of the core wire 31 at a predetermined pitch. The steel wires of the steel wire group constituting the strand 22 can have a diameter of 0.6 mm to 1.0 mm. It is practical to use a steel wire having a diameter of 1.2 m to 1.6 mm as the core wire 31 from the viewpoint of obtaining rigidity of pushing and pulling and keeping the wire size within a predetermined diameter. The side wire 33 is preferably a single layer (single) winding of the steel wire 32 from the viewpoint of ensuring rigidity and cost reduction, but may be a multilayer (multiple) winding.
[0010]
The steel wire 32 is galvanized on the base metal 34, and each steel wire 32 is covered with a plating layer 35 having a thickness of 5 μm or more and 20 μm or less. The surface roughness of the plating layer 35 is Ra: 0.06 μm. The bare metal 34 and the liner 21 have a static friction coefficient of 0.32, whereas the galvanized layer 35 and the liner 21 have a static friction coefficient of 0.26. In the present invention, if the surface roughness of the plating layer 35 is Ra: 0.2 μm or less, it is practically acceptable.
[0011]
The plated layer 35 has a function of smoothing the surface of the steel wire 32 and reducing sliding friction between the side wire 33 and the liner 21 when the wire 3 slides in the longitudinal direction in the liner 21. For this reason, the plating layer 35 may be applied to the entire surface of the steel wire 32 before being wound around the core wire 31, and after being wound around the core wire 31 as shown in FIG. It may be given only to the part which faces.
[0012]
The lower limit of the thickness of the plating layer 35 was determined as follows. With the experimental device shown in FIG. 3, the push-pull control cable 1 having a length of 50 cm and a stroke of ± 30 mm with a load of 200 Newton are 1 million times (corresponding to about 10 years of use in an automobile transmission) The results of repeated durability tests are shown in FIG. As the durability test products, seven products having a thickness t of the plating layer 35 of 4.5 μm or less and seven products having a thickness of 6.0 μm or more are used. In any case, the surface roughness of the plating layer 35 is Ra: 0.06 μm.
[0013]
As shown in FIG. 4, the relationship between the thickness t of the plated layer 35 and the load efficiency has no practical problem even after a million times of repeated tests when the thickness t is 5 μm or more as in the present invention. A load efficiency of about 70% or more can be secured. For this reason, it is not necessary to replace the push-pull control cable 1 even after 1 million repetitive operations.
[0014]
On the other hand, if the thickness t of the plating layer 35 is smaller than 5 μm, the plating layer 35 partially disappears in the curved portion having a small curvature with a large amount of sliding wear, and the base metal 34 is exposed. For this reason, load efficiency falls to 60% or less, and replacement | exchange of the push-pull control cable 1 is needed. The upper limit of the thickness t of the plating layer 35 is set to 20 μm or less because the plating layer 35 thicker than 20 μm is not necessary in practice and increases the cost.
[0015]
The method of galvanization may be either electrogalvanization or hot dip galvanization, and the plating layer 35 may be Fe—Zn alloy plating or Sn—Zn alloy plating. In addition, when grease is interposed on the sliding surface between the side line 33 and the liner 21, it is natural that load efficiency is improved.
[0016]
The steel wire 32 constituting the side wire 33 is uniformly applied to a bus bar having a diameter of 1.5 mm to 2 mm with a galvanization of 25 μm to 60 μm, and the plated bus bar is drawn and elongated to be manufactured to the above dimensions. . In this case, there is an advantage that the structure can be hardened by stretching and the surface of the plated layer can be smoothed, and the galvanized layer after the drawing is uniform and the durability against wear is improved.
The conditions for drawing the dies during the drawing process are as follows.
Number of passes: 19 (preferably 18-22)
Die angle: 17 degrees (possible in the range of 15-20 degrees)
[Brief description of the drawings]
FIG. 1 is a perspective view of a push-pull control cable.
FIG. 2 is an enlarged cross-sectional view of a wire.
FIG. 3 is a side view of the durability test apparatus.
FIG. 4 is a graph showing load efficiency before an endurance test.
FIG. 5 is a graph showing load efficiency after an endurance test.
[Explanation of symbols]
1 Push-pull control cable for automobile transmission 2 Conduit 3 Wire 21 Liner 31 Core wire 33 Side wire 35 Plating layer

Claims (1)

In a push-pull control cable provided with a conduit having a liner made of a resin pipe, and a wire formed by screwing a small diameter side wire around the outer periphery of the core wire, and slidably inserted into the liner,
The core wire is a steel wire having a diameter of 1.2 mm or more and 1.6 mm or less, and the side wire is wound around the outer periphery of the core wire in a single pitch at a predetermined pitch so that the diameter is 0.25 mm or more and 0.6 mm or less. Consisting of a group of steel wires
Zinc plating with a thickness of 5 μm or more and 20 μm or less is applied to the side line to make the surface roughness 0.2 μm or less in Ra display, and after a repeated durability test of 1 million times with a stroke of ± 30 mm at a load of 200 N, A push-pull control cable for an automobile transmission, which can ensure a load efficiency of 70% or more .

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