JPH0628942B2 - Flexible metal tubular body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flexible metal strip 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 as small 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.

[Means for solving problems]

The present invention solves the above-mentioned problems such as the peeling of the coating layer that occurs when the coated metal strip is spirally wound, in other words, a flexible metal strip tubular shape that is easy to manufacture for forming a control cable. The purpose is to develop the body (hereinafter sometimes referred to as flexible tubular body).

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

[Work]

Since the polyvinyl formal layer is formed by baking a thermosetting polyvinyl formal resin, it has high mechanical strength such as abrasion resistance, and also has good adhesion to metal, and the surface of the resin layer is Since it has lubricity, it exhibits excellent resistance to deterioration due to the external force of the strength received during spiral 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 a constitutional example of the coated metal strip used in the present invention.

The flexible tubular body 1 in FIG. 1 is formed by spirally winding a metal band 2 having a baked polyvinyl formal layer (hereinafter simply referred to as a polyvinyl formal layer) 3 as shown in the drawing. Reference numeral 4 denotes a sheath made of an organic polymer such as silicon rubber, polyethylene, polyvinyl chloride, etc. formed on the tubular body 1 by an extrusion method or the like, although not necessarily required. It is an inner stranded wire that is inserted and installed slidably.

The polyvinyl formal layer 3 can be formed by coating and baking a commercially available polyvinyl formal 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 polyvinyl formal varnish that can be used include those conventionally used for manufacturing windings, and those containing polyvinyl formal satisfying the following general formula.

An example of numerical values of x, y, and z in the above formula is x: 7.
0% by weight or more, y: 4 to 9% by weight, z: 0.1% by weight or less. This compound can be obtained, for example, by saponifying polyvinyl acetate to give polyvinyl alcohol and formalizing it.

As the metal strip 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 polyvinyl formal layer 3 has a thickness of 20 to 1
About 100 μm is suitable.

The metal strip 2 used in the present invention may have only the polyvinyl formal layer 3 as shown in FIG. 2, and as shown in FIG. 3, another kind of varnish is applied and baked directly on the metal strip 2. It may have a primary layer 3 '. 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 there is a lubricant on the surface of the polyvinyl formal layer 3, the damage of the layer 3 in the spiral winding process of the metal strip is reduced, and the inner stranded wire 5 inserted into the obtained flexible tubular body 1 is reduced. Sliding in the tubular body becomes even smoother. As the lubricant, for example, a silicon-based lubricant (commercially available products of FSXB2724, FSXB2724 and Dow Corning 2725,
Toray Silicon Co.'s SH-29PA, 30PA, etc., Fluorine-based lubricants (Daikin Industries' Polyflon D-
1, ASTO's AS coat No. 6 etc.) or aliphatic lubricants (commercially available products such as Hoxt's WAXE, Ishihara Yakuhin's UNICON etc.), etc., silicon lubricants and WA
Some lubricants such as XE may be added in advance in the polyvinyl formal varnish used for coating and baking in an amount of about 0.1 to 1.0% by weight, and before being spirally wound. Or a subsequent polyvinyl formal layer 3 on the metal strip 2.
May be applied on top of.

Of the above lubricants, fluorine-based ones are water resistant,
It is particularly preferable because it has excellent salt spray resistance.

The flexible metal strip tubular body of the present invention is used for forming a control cable. The formation of the control cable is, as is clear from FIG. 1, an internal through hole (a hollow portion) of the flexible tubular body. ), The inner stranded wire can be slidably inserted.

Manufacturing example 1.0 mm x 2.6 mm flat iron wire is coated with polyvinyl formal varnish (TVE5225M from Toshiba Chemical Co., Ltd.) 6 times and baked.
Further, a varnish prepared by adding a silicon lubricant SH-29PA (manufactured by Toray Silicon Co., Ltd.) to the above varnish at a resin ratio of 0.5% by weight was applied and baked once to give a skin cover thickness of 0.034 mm × 0.055 mm.
A coated metal strip of Then the metal strip thus obtained is 30 m
Spirally wound at a line speed of / min, inner diameter 3.5 mm
A flexible tubular body was obtained. Peeling of the polyvinyl formal layer did not occur even by this spiral winding process.

〔The invention's effect〕

According to the flexible metal strip tubular body of the present invention, when the metal strip is spirally wound, the baking coating layer of the polyvinyl formal resin is unlikely to cause peeling, breakage, etc. Is also easy to manufacture and the manufactured tubular body is of high quality. Further, since the baked coating layer has excellent mechanical strength such as abrasion resistance and also has a lubricant layer on the surface thereof, it is easy to insert the inner stranded wire, and the sliding smoothness of the inserted inner stranded wire is excellent. In addition, it is possible to form a control cable with excellent corrosion resistance while maintaining these features for a long period of time, and in that case, it is necessary to insert the inner stranded wire directly into the flexible metal band tubular body and interpose a plastic tube between them. It also has excellent control cable formation efficiency.

[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: Polyvinyl formal 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 metal band having a polyvinyl formal layer composed of a baking coating layer of a polyvinyl formal resin is spirally wound, and a lubricant layer is provided on at least the surface of the polyvinyl formal layer. And a flexible metal strip tubular body for slidably inserting an inner stranded wire therein to form a control cable. 2. The flexible metal strip 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 polyvinyl formal layer. 3. The flexible metal strip tubular body according to claim 2, wherein the primary layer is a baked layer which is a layer applied by an electrodeposition coating method.