JP2012121324A - Method of manufacturing rubber sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a rubber sheet that can manufacture a rubber sheet with high work efficiency by facilitating inserter passing of insulation processing during a rubber sheet manufacturing process.SOLUTION: There is provided the method of manufacturing the rubber sheet in which a plurality of steel wires 1 wound around one winding member 2 are bundled and then rubber is coated. The plurality of steel wires 1 are closely contacted in parallel without overlapping each other and a fixing part 4 is included for fixing at least one part of an end side of the plurality of steel wires 1. A solder, an adhesive and induction heating are preferably used as a fixing means.

Description

  The present invention relates to a method for manufacturing a rubber sheet, and more particularly, to a method for manufacturing a rubber sheet that facilitates insertion of an inserter in an insulation process during a rubber sheet manufacturing process and can manufacture a rubber sheet with good workability.

  In recent years, pneumatic radial tires, especially passenger car tires, are required to have low rolling resistance, good riding comfort, and low cost in order to improve the fuel efficiency of automobiles. As an improvement measure, there has been proposed a method of embedding in a rubber in units of bundles arranged and aligned in the belt width direction without twisting steel wires (for example, Patent Documents 1 and 2).

  For rubber sheets with untwisted steel cords, generally, spools are arranged in a number corresponding to the required number of placements on the rubber sheet, and the steel wires wound around the spools are pulled out from a predetermined number of spools, and are aligned to form a bundle. Then introduce it to the guide plate. Then, after the steel wire bundle introduced into the guide plate is guided to the comb-teeth roll, it is manufactured by rolling and coalescing with the separately introduced rubber sheet in a calendar.

  In such a rubber sheet manufacturing method, the steel wire bundle is guided to each of the comb rolls and then sent to the calendar, so when setting a plurality of steel wires to the comb roll in units of bundles, A bundle of steel wires once set or a part of the bundled steel wires may jump out of the comb roll. In this case, the steel wire must be reset and workability is impaired. In particular, a cord composed of a plurality of steel wires has appropriate flexibility, whereas a steel wire alone does not have such flexibility and is light, and therefore easily protrudes from a comb-tooth roll. Further, when the steel wire that has jumped out is set again, it is difficult to distinguish from the steel wires constituting the other bundles, which increases the complexity and significantly lowers the work efficiency.

  As a technique for solving such a problem, Patent Document 3 discloses a method of manufacturing a rubber sheet by bundling a plurality of steel wires and aligning them with a guide plate, and then conducting a calendering treatment after guiding them to a comb tooth roll. A technique for twisting at least a part of the ends of a plurality of steel wires before guiding the plurality of steel wires to the comb teeth is disclosed. According to this, it is possible to easily suppress the steel wire bundle and the individual steel wires constituting the bundle from jumping out of the comb teeth, thereby making it possible to manufacture a rubber sheet with good workability. Further, in Patent Document 4, when a plurality of steel wires are bundled into a bundle and wound by a winding device, the end of the steel wire bundle is twisted in advance to wind the wire to the calendar device. Techniques that facilitate this have been proposed.

JP-A-5-5290 Japanese Patent Laid-Open No. 11-208210 JP 2006-7428 A JP 2002-309492 A

  The technique of patent document 3 manufactures a rubber sheet by a calendar process. However, in the insulation process, which is also a means for manufacturing rubber sheets by coating rubber on steel wires, the twisted diameters of the ends of a plurality of twisted steel cords are large. Has the problem of not being able to.

  Specifically, when producing a rubber sheet by applying insulation treatment without twisting a plurality of steel wires, the steel sheet is embedded in the rubber as a unit of a bundle of steel wires arranged in the belt width direction. Therefore, the plurality of steel wires are positioned according to the hole shape and size of the inserter. For example, when six steel wires having a diameter of 0.225 mm are embedded in rubber as one bundle, the shape of the inserter hole is a horizontally long rectangle of 0.25 mm in the thickness direction and 1.48 mm in the width direction. In this case, when six steel wires having a diameter of 0.225 mm are twisted together using the method of Patent Document 1, the outer diameter is approximately 0.65 mm, which is a thickness far exceeding the 0.25 mm of the inserter hole. Therefore, it is impossible to connect to the inserter.

  Therefore, when the ends of a plurality of steel wires wound on one winding member (for example, a spool) are twisted together, the twisted ends must be removed in order to pass through to the inserter. In other words, the working efficiency is deteriorated, and further, a difference in the drawing length is likely to occur. By winding multiple steel wires around a single winding member at an equal length, the steel wire is prevented from sagging at the unwinding stage of the calendar process or the insulation process. When this occurs, sagging occurs in the steel wire. Due to this slack, there is a problem that the steel wire is likely to come off from the unwinding member, be caught by guides of the unwinding stand, or be disconnected.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber sheet manufacturing method that facilitates insertion of an inserter in an insulation process during a rubber sheet manufacturing process and can manufacture a rubber sheet with good workability.

  As a result of intensive studies to solve the above problems, the present inventors fixed at least a part of the end portions of a plurality of steel wires in a state in which the steel wires are closely contacted in parallel without overlapping each other. The present inventors have found that the above problems can be solved, and have completed the present invention.

That is, the method for producing a rubber sheet of the present invention is a method for producing a rubber sheet in which a plurality of steel wires wound around one winding member are bundled and then coated with rubber.
The plurality of steel wires are closely contacted in parallel without overlapping, and at least a part of the end portions of the plurality of steel wires is fixed.

  In the present invention, the fixing means is preferably direct current heating to solder, an adhesive, or a steel wire. In the present invention, the number of the steel wires is preferably 2 to 6, and in the present invention, the length of the fixing portion formed by the fixing is 5 to 200 mm. preferable. Furthermore, in the present invention, it is preferable that the thickness of the fixing portion formed by the fixing is 108% or less of the diameter of the steel wire, and the width of the fixing portion formed by the fixing is the plurality of the plurality of fixing portions. The width is preferably 108% or less of the width when the steel wires are closely contacted in parallel without overlapping.

  ADVANTAGE OF THE INVENTION According to this invention, the inserter wiring of the insulation process in a rubber sheet manufacturing process can be made easy, and the manufacturing method of the rubber sheet which can manufacture a rubber sheet with sufficient workability | operativity can be provided.

It is the schematic of suitable embodiment of the manufacturing method of the rubber sheet of this invention. It is an enlarged view of an example of the edge part of the bundle | flux of the multiple steel wire of this invention. It is sectional drawing which shows the relationship between the dimension of an inserter hole, and a steel wire diameter.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view of a preferred embodiment of the method for producing a rubber sheet of the present invention. In the illustrated example, a plurality of winding members 2 (spools in the illustrated example) around which a plurality of steel wires 1 are wound, and an inserter 3 into which the steel wires 1 drawn from the winding member 2 are fed. The steel wire 1 is introduced into the inserter 3 from the winding member 2 with a constant tension by a pulling device (not shown). The inserter 3 is provided with a plurality of holes for forming a steel wire bundle, and the steel wire bundle passed through the inserter 3 is fed into an extruder (not shown), coated with rubber, and rubber sheet. It becomes.

  FIG. 2 is an enlarged view of an example of an end portion of a bundle of a plurality of steel wires of the present invention. As shown in the figure, in the present invention, a plurality of (six in the illustrated example) steel wires 1 wound around one winding member (not shown) are brought into close contact in parallel without overlapping, and a plurality of steels are attached. At least a part of the end side of the wire 1 is fixed to form a fixing portion 4. Thereby, the wiring to the inserter 3 of the insulation process which is a rubber sheet manufacturing means becomes easy. Further, since it is not necessary to cut the end portion, the drawing length is not shifted, the slack of the steel wire 1 can be prevented, and the effect that the steel wire 1 is not disconnected can be obtained. Note that the cross-sectional shape of the fixing portion 4 may be a shape that can be easily passed through the hole of the inserter.

  In the present invention, as the means for fixing the plurality of steel wires 1, welding by direct current heating to solder, an adhesive, or steel wires can be suitably used. When using solder, keep the steel wires parallel and in close contact with each other, apply hot-melted solder to the steel wire, and after the solder cools and hardens, polish it with sandpaper or the like until it reaches the desired size and shape. By doing so, the fixing portion 4 is formed. As the solder, lead-free solder can be preferably used. When using an adhesive, make sure that the steel wires are parallel and in close contact with each other, apply the adhesive to the steel wire, and after the adhesive is completely cured, polish the protruding adhesive with a sandpaper etc. 4 may be formed. As the adhesive, a so-called so-called instantaneous adhesive can be suitably used, and commercially available adhesives can be used.

  However, fluxes used for soldering and adhesives are highly flammable, and many are toxic. Therefore, from the viewpoint of health and disaster prevention, it is more preferable that the steel wire is directly energized and heat-welded. In addition, when using a steel filament in which a plurality of steel wires are twisted together using a twisting device, the twisted portion must be cut by direct energization during use. However, since the tip of the steel filament melts and spheroidizes at the time of fusing, or the fusing part is oxidized and quenched, the steel filament becomes brittle and the strength of the steel filament cannot be obtained.

  Therefore, in the present invention, when the steel wire is directly energized and heat-welded, a case with a shape that can be reasonably connected to the hole of the inserter is installed between the electrodes of the directly energized heating device to solve the above-mentioned spheroidization problem. In addition, it is preferable to make the shape easy to pass through the inserter. Further, the above oxidation problem can be solved by blowing an inert gas into the case. Furthermore, embrittlement due to quenching can be prevented by adopting a heat insulating structure in which a heat insulating material is disposed in the case so that the steel filament is not rapidly cooled after welding or a heat insulating structure in which an electric heater or the like is disposed outside. The case is not particularly limited as long as it can withstand the direct current heating temperature, but a ceramic case can be preferably used.

  In the present invention, the number of steel wires to be bundled is not particularly limited and is appropriately determined according to the intended use of the rubber sheet, but is preferably 2 to 6 from the viewpoint of tire performance. .

  In this invention, it is preferable that the length L of the fixing | fixed part 4 is 5-200 mm (refer FIG. 2). If the length of the fixing portion 4 is less than 5 mm, the steel wire 1 may not be sufficiently fixed, and the bundle of steel wires 1 may be unwound. On the other hand, although there is no restriction | limiting in particular about the upper limit of the length of the fixing | fixed part 4, The said effect can fully be acquired if it is 200 mm.

  In the present invention, the thickness T of the fixing portion 4 is preferably 108% or less of the steel wire diameter (see FIG. 2). FIG. 3 is a cross-sectional view showing the relationship between the size of the inserter hole and the diameter of the steel wire. As shown in the figure, the height of the inserter hole 5 of the inserter 3 used for the insulation treatment is usually 1.10 × when the steel wire diameter is d when rubber coating is applied to an untwisted steel cord. This is because it is designed to be about d.

  Furthermore, in the present invention, the width W of the fixing portion 4 is preferably 108% or less of the width when the plurality of steel wires 1 are brought into close contact in parallel without overlapping (see FIG. 2). The width of the inserter hole 5 used for the insulation treatment is such that when rubber coating is applied to a non-twisted steel cord, usually n steel wires having a wire diameter d are arranged (six in the illustrated example). This is because it is designed to be about × d × 1.10.

  In the present invention, it is important to fix a plurality of steel wires 1 wound around one winding member in parallel without overlapping, and fix at least a part of the end portions of the plurality of steel wires 1. There are no other restrictions, and publicly known methods can be used for rubber coating. For example, when the steel wire 1 is coated with rubber, the fixed portion 4 is introduced into the inserter 3 of the extruder so that the bundle of steel wires aligned in parallel is coated with rubber. Thereby, a rubber sheet in which one bundle of steel wires is embedded can be obtained. The method for producing a rubber sheet of the present invention is not limited to the insulation method, and can be applied to a calendar method. For example, a plurality of steel wires wound around one winding member are closely contacted in parallel without overlapping, and at least a part of the end side of the plurality of steel wires is fixed, and then put into a calendar for calendering A rubber sheet can also be obtained by applying (rolling).

  In the present invention, the steel wire 1 may be any steel wire that is usually used for embedding in a rubber sheet. For example, the steel wire that has been heat-treated and further plated with brass is passed through a plurality of drawing dies, and is wet. Examples of the steel wire include wire drawing and wire drawing so that the wire diameter is 0.15 to 0.40 mm. The steel wire 12 used here may be any steel wire that is usually used for a rubber sheet. However, in order to obtain a certain degree of strength, the carbon content is 0.6 to 1.2% by mass. It is preferable. If it is 0.6% by mass or more, an appropriate strength can be secured, and if it is 1.2% by mass or less, an appropriate metal structure can be obtained in the heat treatment step, and the wire can be broken during wire drawing There is no hindrance to production.

Hereinafter, the present invention will be described in more detail with reference to examples.
<Example 1>
A high carbon steel wire rod having a diameter of 5.5 mm containing 0.80% by mass of carbon was subjected to dry drawing until the diameter reached about 1.4 mm, and then subjected to a patenting treatment and a brass plating treatment. Wet wire drawing of this wire to 0.225mm, after straight drawing dies, straightness is corrected using rolls arranged in a staggered pattern, and then steel wires with straightness corrected are wound one by one Six spools were prepared, and these were wound at the same time and wound around one spool, and 40 spools of six steel wires wound around the same spool were prepared.

  The steel wires were brought into close contact with each other at the unwinding ends of the six steel wires wound around one spool, and heat-melted solder was applied thereto. After the solder cooled and hardened, it was polished with sandpaper until it reached the desired size and shape. The obtained steel wire bundle was passed through an inserter of an extruder and coated with rubber to produce a rubber sheet. Solder (Senju Metal Co., Ltd .: Eco Solder M20) was used, and the length of the fixed part was 50 mm, the thickness was 0.24 mm, and the width was 1.45 mm. The inserter hole has a height of 0.25 mm and a width of 1.48 mm.

<Example 2>
A rubber sheet was produced by the same procedure as in Example 1 except that the fixing means was an instantaneous adhesive (Konishi Co., Ltd .: Aron Alpha). The length of the fixed part was 20 mm, the thickness was 0.235 mm, and the width was 1.40 mm.

<Example 3>
A rubber sheet was produced by the same procedure as in Example 1 except that the fixing means was directly heated and energized. The energizing condition is 6 steel. Voltage: 20V Energizing time: 40ms. When energizing, use a ceramic case with a fixed part length of 1mm, thickness of 0.2mm and width of 1.4mm. An inert gas was blown into the inside. An electric heater was arranged around the case.

  In any of Examples 1 to 3, the inserter wiring during the insulation treatment was easy, and a rubber sheet could be manufactured with good workability. In addition, disconnection of the steel wire did not occur.

DESCRIPTION OF SYMBOLS 1 Steel wire 2 Winding member 3 Inserter 4 Fixed part 5 Inserter hole

Claims (8)

In a method for producing a rubber sheet in which a plurality of steel wires wound around one winding member are bundled and then rubber is coated,
A method for producing a rubber sheet, comprising: adhering the plurality of steel wires in parallel without overlapping each other, and fixing at least a part of the end portions of the plurality of steel wires.   The method for producing a rubber sheet according to claim 1, wherein the fixing means is solder.   The method for producing a rubber sheet according to claim 1, wherein the fixing means is an adhesive.   The method for producing a rubber sheet according to claim 1, wherein the fixing means is direct current heating to the steel wire.   The number of the said steel wires is 2-6, The manufacturing method of the rubber sheet as described in any one of Claims 1-4.   The method for producing a rubber sheet according to any one of claims 1 to 5, wherein a length of the fixing portion formed by the fixing is 5 to 200 mm.   The method for manufacturing a rubber sheet according to any one of claims 1 to 6, wherein a thickness of the fixing portion formed by the fixing is 108% or less of a diameter of the steel wire.   The rubber according to any one of claims 1 to 7, wherein a width of a fixing portion formed by the fixing is 108% or less of a width when the plurality of steel wires are closely contacted in parallel without overlapping. Sheet manufacturing method.

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