JPH0628943B2 - Flexible tubular body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flexible tubular body for forming a control cable for automobiles, motorcycles and the like.

[Conventional technology and problems]

Control cables are used as brake cables and clutch cables for automobiles, but the inner stranded wire slides smoothly inside the flexible tubular body, and the force applied to one end of the control cable is reduced as little as possible. It is necessary to tell the other end at.

Conventionally, in order to perform the above smooth sliding, a plastic tube was inserted into a flexible tubular body, and the inner stranded wire was placed in this plastic tube.
Since it takes a lot of labor to insert this plastic tube and it is difficult to manufacture it, the present inventors have made a flexible tubular body by spirally winding a metal band previously coated with a resin. Proposed. Since the inside of this new flexible tubular body is eventually covered with the above resin, it is not necessary to insert a plastic tube.

By the way, since a relatively large force is applied to the resin coating layer when the metal strip coated with the resin is spirally wound, the coating layer may be peeled off and damaged due to processing depending on the resin. Further, the resin coating layer may be required to have heat resistance, as in the case where the control cable is laid near the engine room.

[Means for solving problems]

INDUSTRIAL APPLICABILITY The present invention solves the above-mentioned problems such as peeling of the coating layer that occurs when the coated metal strip is spirally wound, in other words, is easy to manufacture for forming a control cable and has excellent heat resistance. The purpose is to develop a flexible tubular body.

That is, the present invention is characterized in that a metal band having a polyamideimide layer comprising a baking coating layer of a polyamideimide resin is spirally wound, and a lubricant layer is provided on at least the surface of the polyamideimide layer. And a flexible tubular body for slidably inserting an inner stranded wire therein to form a control cable.

[Action]

The baked polyamide-imide layer has excellent heat resistance, and since it is formed by baking a thermosetting polyamide-imide resin, it has high mechanical strength such as abrasion resistance, and also has good adhesion to metal. In addition, since the surface of the resin layer is lubricative, it exhibits excellent resistance to processing deterioration with respect to the external force of the strength received during spirally winding. In addition, since the inner wall surface of the tubular body obtained by spirally winding is made of a lubricating resin layer, the inner stranded wire inserted inside can smoothly slide.

〔Example〕

FIG. 1 is a structural example of a flexible tubular body according to an embodiment of the present invention,
2 and 3 show an example of the structure of the coated metal strip used in the present invention.

The flexible tubular body 1 of FIG. 1 is formed by spirally winding a metal band 2 having a baked polyamideimide layer (hereinafter, simply referred to as polyamideimide layer) 3 as shown in the drawing. Although not necessarily required, 4 is a sheath made of a heat-resistant organic polymer such as silicone rubber, polytetrafluoroethylene, polyether ether ketone, or polyamide formed on the tubular body 1 by an extrusion method or the like. There is an inner stranded wire 5 which is inserted into the tubular body 1 and is slidably installed.

The polyamide-imide layer 3 can be formed by coating and baking a commercially available polyamide-imide varnish on the metal strip 2 under normal conditions by a known coating method such as a dip coating method or an electrodeposition coating method. Examples of the polyamide-imide-based varnish that can be used include, in addition to those conventionally used in the production of windings, those having a structure of the following formula and containing a polyamide-imide having an imide group and an amide group in the polymer chain. be able to.

In the formula, R is And so on. This compound can be obtained by, for example, a method of reacting tricarboxylic acid or its derivative with diamine.

As the metal band 2, one having a width of about 2 to 5 mm and a thickness of about 0.5 to 2.0 mm made of iron, steel, aluminum, copper or the like is suitable, and the thickness of the polyamide-imide layer 3 is 20 to 100.
About μm is appropriate.

The metal strip 2 used in the present invention may have only the polyamide-imide layer 3 as shown in FIG.
As shown in FIG. 3, it may have a primary layer 3 ′ formed by coating and baking another type of varnish directly on the metal strip 2. The primary layer 3'is formed by applying a varnish such as a polyester varnish, an acrylic varnish, or a polyesterimide varnish, which has been used in the conventional production of an insulating enamel wire, by a dip coating method or an electrodeposition coating method and baking the varnish. May be formed. In particular, in the case of electrodeposition coating, the varnish coating at the corners of the metal strip is sufficient, which is advantageous when spirally winding the coated metal strip.
Since a lubricant is present on the surface of the polyamide-imide layer 3, damage to the layer 3 at the time of spirally winding the metal strip is reduced, and the inner stranded wire inserted into the obtained flexible tubular body 1 is reduced. The sliding of No. 5 inside the tubular body becomes smoother. As the lubricant, for example, a silicon-based lubricant (commercial products such as Dow, Corning's FSXB2724 and 2725, Toray Silicon Co.'s SH-29PA, 30PA, etc.), a fluorine-based lubricant (commercially available from Daikin Industries, Ltd.) Polyflon D-1, from Sato
AS coat No. 6 etc.) or aliphatic lubricants (commercial products such as WAXE from Hoechst, UNI-CON from Ishihara Yakuhin, etc.), etc., and some of silicone-based lubricants and fatty-based lubricants The lubricant may be added in advance to the polyamide-imide varnish used for coating and baking in an amount of about 0.1 to 1.0% by weight, and the lubricant on the metal strip 2 before or after being spirally wound. It may be applied on the polyamide-imide layer 3.

Of the above lubricants, silicone-based and fluorine-based ones are particularly preferable because they are excellent in water resistance and salt spray resistance.

The flexible tubular body of the present invention is used for forming a control cable, and the formation of the control cable is as shown in FIG. 1 in the internal through hole (hollow portion) of the flexible tubular body. This can be done by slidably inserting the inner stranded wire.

Production example 1.0mm x 2.6mm rectangular iron wire coated with polyamide-imide varnish (HI-405-30 from Hitachi Chemical Co., Ltd.) 6 times and baked.
The above varnish was coated and baked once with a varnish to which a silicon lubricant SH-29PA (manufactured by Toray Silicon Co., Ltd.) was added at a resin ratio of 0.5% by weight, and a coated metal band with a skin cover thickness of 0.035 mm × 0.053 mm was obtained. Obtained. The metal strip thus obtained was then spirally wound at a line speed of 30 m / min to obtain a flexible tubular body having an inner diameter of 3.5 mm. Peeling of the polyamide-imide layer did not occur even by this spiral winding process.

〔The invention's effect〕

According to the flexible tubular body of the present invention, when the metal strip is spirally wound, the baking coating layer of the polyamide-imide resin is less likely to cause peeling, breakage, etc. Is also easy, and the manufactured tubular body is of high quality. Further, since the baking coating layer has excellent mechanical strength such as abrasion resistance, heat resistance, corrosion resistance such as water resistance and salt water resistance, and a lubricant layer on the surface thereof, insertion of the inner stranded wire is easy and It is possible to form a control cable that has excellent sliding smoothness of the inner stranded wire and that can maintain such characteristics for a long time and withstand wiring in the vicinity of the engine room of the automobile or where water, salt water, etc. are splashed. Since it is not necessary to directly insert the inner stranded wire into the flexible tubular body and to interpose the plastic tube between them, the control cable forming efficiency is also excellent.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of the present invention, FIG. 2 and FIG.
Each of the figures is a sectional view of the coated metal strip used in the present invention. 1: Flexible tubular body, 2: Metal band, 3: Polyamideimide layer, 3 ': Primary layer, 4: Sheath, 5: Inner twisted wire.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Daizo Yamamoto 4-3 Ikejiri, Itami City, Hyogo Prefecture Dainichi Nippon Electric Cable Co., Ltd. Kansai factory (Itami area) (56) Reference JP-A-57-121820 (JP) , A) Japanese Patent Publication Sho 36-13839 (JP, B1)

Claims (3)

[Claims] 1. A spirally wound metal band having a polyamideimide layer made of a baked coating layer of a polyamideimide resin, the polyamideimide layer having a lubricant layer on at least the surface thereof. A flexible tubular body for slidably inserting an inner stranded wire therein to form a control cable. 2. The flexible tubular body according to claim 1, further comprising a primary layer consisting of a coating and baking layer of varnish between the metal strip and the polyamide-imide layer. 3. The flexible tubular body according to claim 2, wherein the primary layer is a baked layer which is a layer applied by an electrodeposition coating method.