WO2012161238A1 - Method for manufacturing pneumatic tire, pneumatic tire, and method and device for manufacturing reinforcing members - Google Patents

Abstract

Provided is a pneumatic tire manufacturing method that enables a reinforcing effect to be more effectively obtained in terms of cost and weight. Also provided is a pneumatic tire that achieves a desired reinforcing effect while satisfying basic performance as a tire. The method for manufacturing a pneumatic tire involves disposing reinforcement members, which are formed by placing layers of reinforcing fiber pieces comprising a plurality of reinforcing fiber pieces, which are obtained by cutting reinforcing fibers at a predetermined length, between a pair of strip-shaped unvulcanized rubber sheets, on the sidewalls in the circumferential direction of the tire. When manufacturing a raw tire, in a tire molding step conducted prior to an extension step, the reinforcing members are attached to the sidewalls in such a manner that the density of the reinforcing fibers has a density gradient that is higher at the end on the tread section side than on the end on the bead section side.

Description

Pneumatic tire manufacturing method and pneumatic tire, and reinforcing member manufacturing method and manufacturing apparatus

The present invention relates to a method for manufacturing a pneumatic tire and a pneumatic tire (hereinafter, also simply referred to as “manufacturing method” and “tire”), and more particularly, to a method for manufacturing a pneumatic tire according to an improvement in the structure of a reinforcing member in a material stage. And a pneumatic tire. The present invention is useful not only for passenger car tires but also for heavy duty tires used in heavy duty vehicles such as trucks and buses.

The present invention also relates to a method and apparatus for manufacturing a reinforcing member (hereinafter also simply referred to as “manufacturing method” and “manufacturing apparatus”), and more specifically, a method for manufacturing a reinforcing member that is suitably used for reinforcing a pneumatic tire or the like. And improvement of manufacturing equipment.

Conventionally, in a pneumatic tire, reinforcement has been carried out by arranging a reinforcing member formed by aligning organic fiber cords or steel cords in a certain direction and rubberizing at each part from the bead portion to the tread portion. It has been broken. For example, Patent Document 1 discloses that a side reinforcing layer formed by impregnating a rubber component in an organic fiber cord is disposed between a carcass layer and a belt layer of a sidewall.

Further, as an improved technique for reinforcing the sidewall portion, for example, Patent Document 2 discloses a pneumatic radial tire in which a fiber reinforcing member in which a nonwoven fabric made of monofilament fibers is covered with rubber is installed in the vicinity of the carcass layer. Patent Document 3 discloses a pneumatic radial tire in which a reinforcing layer formed by covering a nonwoven fabric with rubber is provided inside and outside the radial width of the radial carcass, and the radial carcass is sandwiched between these reinforcing layers. It is disclosed. Further, Patent Documents 4 and 5 disclose pneumatic safety tires in which rubber-filament fiber composites are disposed on the sidewall portions in order to improve run-flat running performance.

However, the reinforcement member generally used in the past is made of a rubber composite material in which organic fibers or steel single wires or twisted cords are aligned in a certain direction. However, there was a difficulty that it took a lot of man-hours. In addition, since the cord cut surfaces that do not have an adhesive action with the rubber are arranged at regular intervals at the end portion of the reinforcing member, the cut surfaces serve as a starting point for the separation of the cord and the rubber, resulting in a rough road. There is also a problem that there is an unavoidable risk of separation starting from the end of the reinforcing layer due to running or heavy load running.

On the other hand, in the manufacturing process of tires, when manufacturing belts, carcasses, etc., the ends of organic fibers or steel single wires or twisted cords remain with a half length. Since regular arrangement is indispensable, such a half-length end material cannot be used and must be disposed of.

On the other hand, the present inventors use a reinforcing member formed by coating a short reinforcing fiber satisfying a predetermined condition with rubber, thereby preventing the basic performance as a tire without the above problems. It has been found that a pneumatic tire that achieves a desired reinforcing effect while satisfying the above can be obtained. Here, a nonwoven fabric is known as a reinforcing material using such short fibers. As a general method for producing a nonwoven fabric, there is a method using a fiber opening device. The fiber opening device is a device in which massive fibers are introduced while the needle roller rotates, and the fibers are opened and spread in a sheet form. The fibers dispersed in the form of a sheet are finally crimped by a crimping roller to form a nonwoven fabric. The non-woven fabric thus produced has a uniform density as a whole, although there are variations in manufacturing.

Also, when manufacturing a pneumatic tire, normally, after the forming process of assembling the members and forming the raw tire, an expansion process is performed to expand the raw tire into the shape of the product tire. In this expansion process, the expansion rate differs between the tread portion side and the bead portion side of the raw tire, and the tread portion side is greatly expanded as compared with the bead portion side. Therefore, when the material having a uniform density manufactured as described above is used for, for example, the side portion, the product tire finally obtained has a fiber density of 2 on the tread portion side and the bead portion side. The difference is nearly double, and in heavy-duty tires used for trucks and buses, the difference is twice or more. That is, in this case, the fiber density on the bead portion side becomes excessive and more fibers than necessary are used, which is disadvantageous in terms of cost and weight.

Therefore, when reinforcing a tire using a reinforcing member that satisfies the above predetermined conditions, the unevenness of the density of the reinforcing fibers in the product tire is reduced, and the reinforcing effect is more efficiently in terms of cost and weight. It has been desired to establish a technology that can be obtained.

Further, conventionally, it is known to apply a reinforcing member in which a plurality of short fibers are sandwiched between a pair of rubber sheets to a pneumatic tire. As described above, a nonwoven fabric is known as a reinforcing material using such short fibers, and a general method for producing a nonwoven fabric includes a method using a fiber opening device.

As a technique for applying a reinforcing member using a short fiber to a tire, for example, in Patent Document 6, a short fiber is blended with at least one kind of rubber, a modulus b in a short fiber orientation direction, and a modulus a in a direction perpendicular thereto. Two or more rubber reinforcing layers having a ratio b / a of 1.5 or more are provided on at least a part of the bead portion from the tire shoulder portion so that the short fiber orientation directions intersect with each other, and approximately half of the short fibers are provided. A pneumatic tire is disclosed in which the tire is disposed at an angle of + 25 ° to + 65 ° with respect to the tire circumferential direction, and the remaining short fibers are disposed at an angle of −25 ° to −65 ° with respect to the tire circumferential direction.

Moreover, as a prior art including the dispersion | distribution process of a fiber reinforced resin sheet, for example, in patent document 7, on a sheet-like resin containing fiber material which made thermoplastic resin powder adhere to many continuous long fibers, many continuous A strip-shaped cut piece of a fiber-reinforced thermoplastic resin sheet reinforced with long fibers is dispersed so that the fiber orientation direction of the strip-shaped cut piece does not coincide with the fiber orientation direction of the sheet-shaped resin-containing fiber material, A method for producing a fiber composite sheet in which this is heated and pressurized to melt and integrate a thermoplastic resin is disclosed. Furthermore, in Patent Document 8, a chopped fiber bundle in which reinforcing fibers are substantially aligned in one direction is continuously run through a plurality of continuous fiber bundles, and widening means disposed in the middle of the run. A chopped fiber bundle that widens the fiber bundle so that the ratio between the width W1 of the fiber bundle before widening and the width W2 of the fiber bundle after widening is within a predetermined range, and then simultaneously cuts the plurality of widened fiber bundles. A manufacturing method is disclosed.

Furthermore, in Patent Document 9, for a long elastic sheet in which short fiber groups are oriented in the longitudinal direction of the sheet, the orientation is alternately changed for each predetermined dimension from one surface to the other surface of the elastic sheet. A method for forming an elastic body containing oriented short fibers is disclosed in which a cut is made, and an elastic body in which short fiber ends are exposed on both sides is formed by alternately bending, laminating and pressing along the cut. Furthermore, Patent Document 10 discloses a device for repeatedly forming a fiber yarn nip by an apparatus for repeatedly supplying a fiber bundle in an arbitrary fiber direction from a magazine roll of fiber yarns during production of a thermosetting resin product preform. A supply device having a pair of first and second driven feed rollers for supplying fiber yarns from a magazine roll, a cutting device for cutting the fiber yarns to a desired length, and a pneumatically driven fiber extrusion disposed downstream of the cutting device An arbitrary fiber-directional fiber comprising a device, wherein the first feed roller pair is driven at a slightly lower feed rate than the second feed roller pair, and the fiber extrusion device comprises an oblong tube sleeve having a turbulent air passage A bundle feeder is disclosed.

As described above, as a general method for producing a nonwoven fabric, there is a method using a fiber opening device. In order to spread the spread short fibers at a uniform density, the short fibers are dispersed by a spreading means. It must be manually set at the material inlet at a uniform density. It is not easy to feed the short fibers that have been cut in advance at a uniform density, and it is necessary to feed the short fibers immediately while measuring the short fibers. In particular, when steel fiber short fibers are used as the reinforcing fibers, if the short fibers are entangled with each other, they cannot be easily unraveled. It becomes difficult.

Therefore, establishment of a technique capable of supplying a certain amount of short fibers in a certain time without producing such a problem of entanglement between short fibers and manufacturing a reinforcing member having a uniform density is desired. It was rare.

Also, depending on the purpose of reinforcement, there may be a need for a reinforcing member in which the density of the short fibers is positively changed for each part, and the realization of a reinforcing member having a portion where the density of the short fibers is different has been desired.

Furthermore, depending on the purpose of reinforcement, a reinforcing member in which short fibers are oriented in a certain direction may be required, and the realization of a reinforcing member reinforced by short fibers oriented in a certain direction has been desired.

JP 2006-142877 A (Claims etc.) JP-A-8-40023 (Claims etc.) JP 2002-331808 A (claims, etc.) Japanese Patent Laid-Open No. 11-129712 (claims, etc.) Japanese Patent Laid-Open No. 11-240307 (claims, etc.) JP-A-11-334323 (Claims etc.) Japanese Patent Application Laid-Open No. 8-150691 (claims, etc.) JP 2009-62648 A (Claims etc.) JP-A-6-71776 (claims, etc.) Japanese National Patent Publication No. 9-505023 (claims, etc.)

Therefore, an object of the present invention is to reduce the cost and the cost of reinforcing a tire using a reinforcing member that can be manufactured inexpensively and easily, and that can use the scrap material that has been discarded in the past. The object of the present invention is to provide a method of manufacturing a pneumatic tire that can obtain a reinforcing effect more efficiently in terms of weight, and thereby a pneumatic tire that achieves a desired reinforcing effect while satisfying the basic performance as a tire. It is to provide.

Another object of the present invention is to manufacture a reinforcing member using reinforcing fiber pieces of a predetermined length, without causing a problem of entanglement between the reinforcing fiber pieces, and a certain amount of reinforcing fiber pieces in a certain time. An object of the present invention is to provide a reinforcing member manufacturing method and manufacturing apparatus capable of supplying a reinforcing member having a uniform density.

Still another object of the present invention is to manufacture a reinforcing member using reinforcing fiber pieces of a predetermined length, without causing a problem of entanglement between the reinforcing fiber pieces, and a certain amount of reinforcing fiber pieces in a fixed time. Therefore, the reinforcing fiber piece can provide a reinforcing member manufacturing method and a manufacturing apparatus capable of manufacturing a reinforcing member having a uniform density that is different for each part.

Still another object of the present invention is to produce a reinforcing member using a reinforcing fiber piece of a predetermined length, without causing a problem of entanglement between reinforcing fiber pieces, and a certain amount of reinforcing fiber in a certain time. It is an object of the present invention to provide a reinforcing member manufacturing method and a manufacturing apparatus capable of manufacturing a reinforcing member capable of supplying pieces and having a uniform density and reinforcing fiber pieces oriented in a certain direction.

As a result of intensive studies, the present inventors have determined that the weight density of the reinforcing fiber piece is one end at the other end as a reinforcing member having a specific structure using the reinforcing fiber piece that satisfies a predetermined condition in the green tire molding stage. The present invention has been completed by finding that the above-mentioned problems can be solved by using a material having a density gradient that becomes higher with respect to the end of the substrate.

That is, the pneumatic tire manufacturing method of the present invention has a pair of left and right bead portions and sidewall portions, and a tread portion continuous between both sidewall portions, and a pair of strip-shaped unvulcanized portions on the sidewall portions. Manufacture of a pneumatic tire in which a reinforcing member formed by interposing a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces obtained by cutting reinforcing fibers into a predetermined length between rubber sheets is annularly arranged in the tire circumferential direction A method,
In the tire molding process prior to the expansion process at the time of raw tire production, as the reinforcing member, the density density of the reinforcing fiber pieces is higher than the bead part side end part at the tread part side end part. What has it is stuck to the said side wall part, It is characterized by the above-mentioned.

In the manufacturing method of the present invention, the reinforcing member has a density gradient in which the weight density of the reinforcing fiber pieces is 1.5 times or more at the tread portion side end portion with respect to the bead portion side end portion. Is preferably used. Further, as the reinforcing member, it is preferable to use a material having a basis weight density of the reinforcing fiber pieces that is different between the tread portion side and the bead portion side from the center in the width direction of the reinforcing member. It is also preferable to use one in which the weight density of the reinforcing fiber pieces continuously changes from the tread portion side end portion to the bead portion side end portion.

The pneumatic tire of the present invention is characterized by being manufactured by the method for manufacturing a pneumatic tire of the present invention.

In the tire of the present invention, the basis weight density of the reinforcing fiber pieces is preferably 50 g / m ² or more and 1500 g / m ² or less, and the length of the reinforcing fiber pieces is preferably 15 mm or more. The diameter of the fiber piece is preferably in the range of 0.07 mm to 0.60 mm. In the tire of the present invention, an inorganic fiber can be suitably used as the reinforcing fiber.

In addition, as a result of intensive studies, the present inventors have continuously performed the process of cutting the reinforcing fiber into a predetermined length to obtain the reinforcing fiber piece immediately before the reinforcing fiber piece is sprayed. The inventors have found that this can be solved, and have completed the present invention.

That is, the method for manufacturing a reinforcing member of the present invention includes a reinforcing member in which a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of belt-shaped unvulcanized rubber sheets. A manufacturing method of
A cutting step of cutting the reinforcing fibers to produce the plurality of reinforcing fiber pieces, and the reinforcement on the one strip-shaped unvulcanized rubber sheet from above one of the strip-shaped unvulcanized rubber sheets extending in the longitudinal direction. A spreading step of spreading the fiber pieces to form the reinforcing fiber piece layer; and supplying the other of the belt-like unvulcanized rubber sheets on the one belt-like unvulcanized rubber sheet and superposing the one and the other A step of interposing the reinforcing fiber piece layer between the belt-shaped unvulcanized rubber sheets, and a pressure-bonding step of pressing the one and the other belt-shaped unvulcanized rubber sheets against each other,
The cutting step and the spraying step are performed continuously.

In the production method of the present invention, in spreading the reinforcing fiber pieces through the guide body that opens only in the vertical direction in the spreading step, the width of the one band-shaped unvulcanized rubber sheet is used as the guide body. It is preferable to use one having a width along the direction that is wider at the lower end than at the upper end and that gradually increases from above to below.

Further, in the production method of the present invention, in spreading the reinforcing fiber pieces through the guide body that opens only in the vertical direction in the spreading step, the one strip-like unvulcanized rubber sheet is used as the guide body. It is also preferable to use the one having a narrowed portion whose width along the longitudinal direction is narrower at the lower end than at the upper end and whose width gradually decreases from above to below. In this case, as the guide body, it is more preferable to use a guide having a vertical portion that does not vary in width along the longitudinal direction of the one band-like unvulcanized rubber sheet, below the narrowed portion. It is more preferable to use a lower end portion of the guide body whose width d in the longitudinal direction of the one band-like unvulcanized rubber sheet is 1.0 times or less the length of the reinforcing fiber piece.

Furthermore, in the production method of the present invention, it is preferable to vibrate the one band-shaped unvulcanized rubber sheet in the spraying step, and more preferably, the one band-shaped unvulcanized rubber sheet has a vibration frequency of 1 Hz to 1 kHz. Vibrate with.

Further, the reinforcing member manufacturing apparatus of the present invention is a reinforcing member in which a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of belt-shaped unvulcanized rubber sheets. Manufacturing equipment,
Cutting means for cutting the reinforcing fibers to produce the plurality of reinforcing fiber pieces, and the reinforcing material on the one belt-like unvulcanized rubber sheet from above one of the belt-like unvulcanized rubber sheets extending in the longitudinal direction. Sprinkling means for sprinkling fiber pieces to form the reinforcing fiber piece layer, and supplying the other of the band-shaped unvulcanized rubber sheet on the one band-shaped unvulcanized rubber sheet and superposing the one and the other A supply means for interposing the reinforcing fiber piece layer between the belt-shaped unvulcanized rubber sheets, and a pressure-bonding means for pressing the one and the other belt-shaped unvulcanized rubber sheets against each other,
The cutting means and the spraying means are provided integrally.

In the production apparatus of the present invention, between the one band-shaped unvulcanized rubber sheet and the spreading means, a pair of wall portions parallel to the longitudinal direction of the one band-shaped unvulcanized rubber sheet, A guide body in which an interval between a pair of wall portions is narrower than a width of the one band-shaped unvulcanized rubber sheet, and a surface of the one band-shaped unvulcanized rubber sheet from the lower end of the guide body It is preferable that the distance h is 5 times or less the length of the reinforcing fiber piece. In this case, more preferably, the guide body further includes a pair of wall portions parallel to the width direction of the one band-shaped unvulcanized rubber sheet and opens only in the vertical direction.

In the manufacturing apparatus of the present invention, a guide body that opens only in the vertical direction is installed between the spreading means and the one band-shaped unvulcanized rubber sheet, It is also preferable that the width of the vulcanized rubber sheet along the width direction is wider at the lower end than at the upper end and has a portion that gradually increases from above to below.

Furthermore, in the manufacturing apparatus of the present invention, a guide body that opens only in the vertical direction is installed between the spreading means and the one strip-shaped unvulcanized rubber sheet, and the one strip-shaped uncoated belt of the guide body. It is also preferable that the vulcanized rubber sheet has a narrowed portion in which the width along the longitudinal direction is narrower at the lower end than at the upper end, and the width gradually decreases from the upper side to the lower side. In this case, it is more preferable that the guide body has a vertical portion where the width along the longitudinal direction of the one band-like unvulcanized rubber sheet does not vary below the throttle portion. Moreover, it is more preferable that the width d of the lower end portion of the guide body in the longitudinal direction of the one band-like unvulcanized rubber sheet is 1.0 times or less the length of the reinforcing fiber piece.

Furthermore, the manufacturing apparatus of the present invention preferably includes a vibration generating mechanism for vibrating the one band-shaped unvulcanized rubber sheet. In this case, the vibration frequency of the vibration generating mechanism is preferably in the range of 1 Hz to 1 kHz.

According to the present invention, the above configuration can provide a method for manufacturing a pneumatic tire that can obtain a reinforcing effect more efficiently in terms of cost and weight, and thereby, basic performance as a tire. It is possible to obtain a pneumatic tire that achieves a desired reinforcing effect while satisfying the above.

Further, in the method and apparatus for manufacturing a reinforcing member of the present invention, a cutting step of cutting a reinforcing fiber to produce a plurality of reinforcing fiber pieces, and a dispersion for spreading the reinforcing fiber pieces on a belt-shaped unvulcanized rubber sheet Since the steps are performed continuously, it becomes possible to supply a certain amount of reinforcing fiber pieces in a certain time without causing a problem of entanglement between the reinforcing fiber pieces. Furthermore, in the method and apparatus for manufacturing a reinforcing member according to the present invention, since a plurality of reinforcing fiber pieces are spread in advance on one rubber sheet, the reinforcing fiber pieces after spreading are flat in a lying state. It is supported from below by a rubber sheet. As a result, since the method of lodging is random if the supporting rubber surface is flat, the orientation direction of the reinforcing fiber pieces can be easily randomized, and the distribution can be easily made uniform. It became. Therefore, according to the reinforcing member manufacturing method and manufacturing apparatus of the present invention, it is possible to easily manufacture a reinforcing member having a uniform density. Furthermore, according to the manufacturing method and manufacturing apparatus of the reinforcing member of the present invention, there is a merit that a reinforcing member having a small thickness can be obtained as compared with the prior art.

Furthermore, in the manufacturing method and the manufacturing apparatus of the reinforcing member of the present invention, the dispersion of the reinforcing fiber pieces is performed via a guide body whose width along the width direction of the rubber sheet is gradually increased from the upper side to the lower side. By doing so, it is possible to manufacture a reinforcing member in which the reinforcing fiber pieces have different densities for each part. Therefore, according to the reinforcing member manufacturing method and manufacturing apparatus of the present invention, it is possible to easily manufacture a reinforcing member in which the reinforcing fiber pieces have a uniform density that varies from site to site.

Furthermore, in the method and apparatus for manufacturing a reinforcing member of the present invention, the dispersion of the reinforcing fiber pieces is such that the width along the longitudinal direction of the rubber sheet is narrower at the lower end than the upper end, and gradually decreases from above to below. By carrying out through the guide body which has the part to do, it becomes possible to manufacture the reinforcement member by which the reinforcement fiber piece was orientated to the fixed direction. Therefore, according to the reinforcing member manufacturing method and manufacturing apparatus of the present invention, it is possible to easily manufacture a reinforcing member having uniform density and reinforcing fiber pieces oriented in a certain direction.

It is a width direction one side sectional view showing an example of the pneumatic tire of the present invention. It is a schematic diagram which shows an example of the reinforcement member which concerns on this invention. It is a schematic diagram which shows an example of the reinforcement member in the material stage which can be used for this invention. (A), (b) is explanatory drawing which shows the state of the protrusion input with respect to a tire side part. It is a graph which shows the difference in the effect with respect to protrusion input of the case where the length of a reinforcing fiber is short (a) and the case where it is long (b). It is a partially notched front view which shows one Embodiment of the manufacturing method and manufacturing apparatus of the reinforcement member of this invention. It is sectional drawing which follows the II line | wire of FIG. It is a partially broken perspective view which shows the reinforcement member which concerns on this invention. It is a partially notched front view which shows other embodiment of the manufacturing method and manufacturing apparatus of the reinforcement member of this invention. FIG. 10 is a sectional view taken along line II-II in FIG. 9. It is a partially broken perspective view which shows the reinforcement member which concerns on this invention. (A)-(c) is explanatory drawing which shows the variation of the guide body based on this invention. It is explanatory drawing which shows the relationship between the cross-sectional shape of a guide body, and the dispersion state of a reinforcing fiber. It is a partially notched front view which shows other embodiment of the manufacturing method and manufacturing apparatus of the reinforcement member of this invention. It is sectional drawing which follows the III-III line | wire of FIG. It is a partially broken perspective view which shows the reinforcement member which concerns on this invention. (A)-(c) is explanatory drawing which shows the variation of the guide body based on this invention. It is explanatory drawing which shows the state which does not provide a vertical part in a guide body. It is explanatory drawing which concerns on the evaluation method of the orientation in an Example.

Hereinafter, embodiments of the present invention will be described in detail.
First, a method for manufacturing a pneumatic tire and a pneumatic tire according to the present invention will be described.
In FIG. 1, the cross-sectional view of the width direction of an example of the pneumatic tire of this invention is shown. The illustrated pneumatic tire includes a pair of bead portions 7, a pair of sidewall portions 8 connected to the bead portions 7, and a tread portion 9 straddling the both sidewall portions 8, and these portions are embedded in the bead portion 7. A carcass 2 made of at least one carcass ply that is reinforced between the pair of bead cores 1 is provided. Further, two belt layers 3 arranged so as to cross each other and a belt reinforcing layer 4 arranged so as to cover the entire width thereof are arranged outside the crown portion tire radial direction of the carcass 2. . Further, a bead filler 6 is disposed outside the bead core 1 in the tire radial direction.

In the tire according to the present invention, reinforcing members 5 made of reinforcing fiber pieces and rubber covering the reinforcing fiber pieces are annularly arranged in the tire circumferential direction in the sidewall portion. FIG. 2 shows a schematic diagram of an example of a reinforcing member according to the present invention. This figure shows the dispersion state of the reinforcing fiber pieces when viewed from the direction perpendicular to the surface of the reinforcing member. As shown in the figure, the reinforcing member according to the present invention includes a reinforcing fiber piece 101 plated or adhesive-treated and a rubber 102. More specifically, the reinforcing member is reinforced between a pair of belt-shaped unvulcanized rubber sheets. A reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces obtained by cutting fibers into a predetermined length is interposed. Further, as shown in the figure, the reinforcing fiber piece 101 has at least one end that terminates in the reinforcing member, that is, is composed of a short length of fiber that does not continuously extend between the widthwise ends of the reinforcing member. . Further, as shown in the drawing, the reinforcing fiber piece 101 is embedded in the rubber 102 so that a projected portion obtained by projecting the reinforcing fiber piece 101 in a direction perpendicular to the reinforcing member intersects at least partially. The reinforcing member according to the present invention has a planar shape having a thickness.

By adopting such a configuration, it has become possible to use the end material that has conventionally been waste as the reinforcing fiber piece 101 of the reinforcing member, and it has become possible to effectively use the waste material. In addition, unlike the conventional cord reinforcing layer, the reinforcing member according to the present invention does not require a process such as a stranded wire or draw rolling, and thus is easy to manufacture, and is excellent in cost. ing. Further, in the reinforcing member according to the present invention, since the cross-sections of the reinforcing fiber pieces are not arranged at the end portions, there is no problem of separation starting from the reinforcing member end portions.

Here, when manufacturing the pneumatic tire of the present invention, as the reinforcing member 5 in the material stage before sticking, the weight density of the reinforcing fiber pieces is relative to the bead portion side end portion at the tread portion side end portion. It is important to use one having a density gradient that increases. That is, in the tire molding process before the expansion process at the time of raw tire production, the reinforcing member 5 having a density gradient such that the weight density of the reinforcing fiber pieces is higher at the tread portion side end portion than the bead portion side end portion. And affixed to the sidewall portion 8. Preferably, the reinforcing member 5 has a density gradient in which the basis weight density of the reinforcing fiber pieces is 1.5 times or more, particularly about twice as much as the bead part side end part at the tread part side end part. Use. Since the expansion rate at the time of molding differs depending on the tire size, the preferable condition of the density gradient of the weight density of the reinforcing fiber pieces varies depending on the tire size, and specifically, for example, 1.8 to 2.3 times.

As described above, when manufacturing a pneumatic tire, an expansion process for expanding the raw tire into the shape of the product tire is usually performed after the forming process of assembling the members and forming the raw tire. Since the expansion rate differs between the tread portion side and the bead portion side of the raw tire, if a reinforcing member having a uniform density is used in the material stage before being attached to the tire, the tread portion side and the bead portion are expanded after expansion. There will be a difference of nearly twice the density of the reinforcing fiber pieces on the side. In the present invention, since the reinforcing member 5 having a difference in basis weight between the tread portion side and the bead portion side is attached to the sidewall portion 8 in the molding step in advance, the raw tire is molded. In the final product tire obtained by expanding the tread portion side and the bead portion side at different expansion rates in the expansion process, the basis weight density is uniform between the tread portion side and the bead portion side of the reinforcing member 5. Can be Accordingly, it is possible to efficiently reinforce using a minimum amount of reinforcing fiber pieces, and it is possible to obtain a reinforcing effect more efficiently in terms of cost and weight.

As the reinforcing member 5 at the material stage used in the present invention, specifically, for example, as shown in FIG. 3, the weight of the reinforcing fiber piece is between the tread portion side and the bead portion side from the center in the width direction of the reinforcing member 5. Different densities can be used. That is, the reinforcing member 5 having a two-stage density gradient in which the area having a relatively high basis density and the area having a low basis weight are divided into two on the tread part side and the bead part side is used. In this case, two types of fabric density may be set. Moreover, although not shown in figure, what has the density gradient from which the fabric density of a reinforcing fiber piece changes continuously from the tread part side edge part to a bead part side edge part can also be used as the reinforcement member 5. “Continuous” in this case may be changed uniformly or may be changed in accordance with the expansion rate.

In the pneumatic tire of the present invention obtained as described above, the difference in the areal density of the reinforcing fiber pieces in the reinforcing member 5 between the bead portion side and the tread portion side can be reduced. In particular, when a member having a density gradient in which the weight density of the reinforcing fiber pieces continuously changes from the tread portion side end portion to the bead portion side end portion is used as the reinforcing member 5, manufacturing variations include. However, the basis weight density of the reinforcing fiber pieces in the reinforcing member 5 is uniform from the bead portion side to the tread portion side.

In the pneumatic tire shown in FIG. 1, the reinforcing member 5 is disposed in the region from the end of the belt layer 3 to the vicinity of the upper end of the bead filler 6. In the present invention, the reinforcing member is a side wall portion. Any material may be used as long as it is disposed in at least a part of the outside of the carcass ply. Specifically, it is disposed in at least a part of the region from the end of the belt layer 3 to the vicinity of the upper end of the bead core 1. By arranging the reinforcing member in at least a part of the side wall portion, it is possible to improve the side cut resistance, and particularly, even when the ply structure is simplified for weight reduction of the tire, A significant decrease in side cut resistance can be suppressed. Preferably, the cut resistance of the entire sidewall portion can be improved by disposing the entire region from the end portion of the belt layer 3 to the vicinity of the upper end of the bead core 1.

In other words, by simplifying the ply structure by reducing the number of two carcass plies to one, or by lowering the carcass ply winding height, in addition to reducing the weight of the tires, the direct material cost, molding man-hours, etc. In this case, however, there is a concern that the strength of the ply is insufficient. In particular, since the carcass ply resists the projection input by a high tension, there is a concern that the cutting performance at the side portion may be significantly reduced due to the lack of this strength. FIG. 4 is an explanatory view showing a state of projection input to the tire side portion. As shown in the drawing, when the tire side part receives the input of the protrusion 100 from the road surface or curb, a carcass ply may break down due to a sharp protrusion whose tip R is 20 mm or less. Many. The reason is that, as shown in FIG. 4 (a), when the projection 100 is pushed into the tire, a tensile stress acts locally on the carcass ply, and this stress exceeds the strength of the ply cord. Then, the carcass ply will break. On the other hand, as shown in FIG. 4B, by arranging the reinforcing member 5 on the outside of the carcass ply, the reinforcing member 5 efficiently shares the tension applied to the carcass ply when the protrusion 100 penetrates. This makes it possible to prevent the carcass ply from being broken. Therefore, the reinforcing fiber preferably has the same strength as the carcass ply.

Further, the length of the reinforcing fiber piece is preferably 15 mm or more, more preferably 20 mm or more, and the upper limit is not particularly limited as long as it is up to the height of the sidewall portion of the applied tire. Particularly preferably, it is in the range of 25 mm to 40 mm. If the length of the reinforcing fiber piece is too short, the penetration of the projection cannot be completely covered when the projection 100 is input, and the carcass ply 2 cannot be protected from local tension, and the ply cord may be broken. Further, the effect of improving the side cut resistance is reduced (see FIG. 5A). On the other hand, if the length of the reinforcing fiber piece is 15 mm or more, the effect can be exhibited even for sharp projection input (see FIG. 5B). Note that the tension generated in the carcass ply is not local to the protrusion having R of 20 mm or more. Therefore, since the frequency of breakage of the carcass ply is reduced, here, a case is assumed in which the tip R has a radius of 20 mm or less.

Furthermore, in the present invention, the weight density of the reinforcing member is 50 g / m ² or more and 1500 g / m ² or less, particularly 80 g / m ² or more and 500 g / m ² or less, more preferably 100 g / m ² or more and 200 g / m ² or less. It is preferable to use those. If the basis weight is less than 50 g / m ² , the strength of the reinforcing member may be insufficient. On the other hand, when the fabric density exceeds 1500 g / m ² , expandability and moldability deteriorate. Here, in the present invention, the basis weight density of the reinforcing member 5 means the total weight of the reinforcing fiber pieces per unit area in one layer of the reinforcing member. That is, the total weight (g) of the reinforcing fiber pieces 101 per layer of the reinforcing member included in the unit area (1 m ² ) is the basis weight in the present invention.

Furthermore, it is preferable to use the reinforcing fiber piece having a diameter in the range of 0.07 mm to 0.60 mm, particularly 0.12 mm to 0.34 mm. If the diameter of the reinforcing fiber piece is too small, the cost in the wire drawing process for obtaining a thin wire diameter increases, and the number of reinforcing fiber pieces to be spread increases, resulting in an increase in cost. On the other hand, if the diameter of the reinforcing fiber piece is too large, the bending fatigue property is deteriorated, and the reinforcing fiber piece may be broken due to compression deformation during traveling at a low internal pressure.

In the present invention, it is not necessary that all the reinforcing fiber pieces used for the reinforcing member have a single length and diameter, and a mixture of reinforcing fiber pieces having a plurality of types of lengths and diameters may be used. However, it is preferable to use a material having a length and diameter within the above range. In particular, if the length of the reinforcing fiber piece is too long, the uniformity of the reinforcing member is impaired, which is not preferable from the viewpoint that the uniformity in the circumferential direction of the tire shape and tire rigidity, which is a component that determines uniformity. The cross-sectional shape of the reinforcing fiber piece is basically circular, but a polygonal shape such as an ellipse or a triangle may be used.

In the present invention, any material may be used as the reinforcing fiber, and it can be appropriately selected from various materials usually used for tire reinforcing members. Specifically, for example, inorganic fibers include metal fibers such as steel filaments and glass fibers, and organic fibers include aromatic polyamide fibers, fatty acid polyamide fibers, polyester fibers, polyparaphenylenebenzeneoxazole fibers, and polyvinyl alcohol-based synthetics. Examples thereof include fibers and carbon fibers. In the present invention, among the above, it is preferable to use inorganic fibers, particularly steel filaments, as the short fibers.

The above-mentioned reinforcing fibers made of inorganic fibers or organic fibers are used in the manufacturing process of tire reinforcing cords, such as end materials (waste made from residual yarn) generated in the post-plating wire drawing process or stranded wire process, It can be manufactured from mill ends generated in the cord rolling process. In the present invention, since such a conventionally discarded scrap material can be used, the cost can be greatly reduced as compared with the conventional one, and the waste can be reduced. is there.

That is, a metal cord such as a steel cord is manufactured by unwinding a filament from a plurality of reels around which a single filament wire that has been plated is wound, and twisting the filament bundle using tension. A non-metallic cord made of organic fibers or the like is manufactured by performing a dipping process in which an adhesive is applied to a twisted filament bundle. When manufacturing a metal twisted cord, when any one of the reels is emptied, the remaining filaments are discarded even if they remain on the other reels. Also, the adjustment portion at the end of the cord is discarded when the manufacturing process is stopped for adjustment and then restarted. Furthermore, since both the metal cord and the non-metallic cord use the tension to manufacture the reinforcing member, the cord end portion that cannot physically secure the tension is also discarded. In the present invention, the reinforcing member can be formed by effectively using the end material of the cord generated in each process in manufacturing the tire.

In addition, a technique for improving the performance on ice by incorporating extremely microfibers having a length of about 5.0 mm or less, usually 2 mm to 3 mm, into the tread rubber as a short fiber is well known. However, in consideration of the effective use of the waste material as described above, if the end material of the cord is cut into micro short fibers and used, the number of manufacturing steps and cost increase. In the present invention, if the reinforcing fiber pieces to be used do not have a certain length and basis weight, the reinforcing fiber pieces do not intersect with each other, or even if they intersect, a sufficient reinforcing effect in strength and rigidity can be obtained. Absent. Therefore, it is preferable to use a reinforcing fiber piece having the above length, basis weight, and the like. However, if only a short reinforcing fiber piece or only a long reinforcing fiber piece is used, a sufficient reinforcing effect may not be obtained or there may be a problem in durability.

Further, since the reinforcing fiber is embedded in rubber to form a reinforcing member, it is necessary to be plated or treated with an adhesive in order to ensure adhesion with the rubber. That is, in the present invention, when the reinforcing fiber is a metal fiber, a plated one is used, and when the reinforcing fiber is an organic fiber, an adhesive-treated one is used. In a metal fiber such as a steel filament, for example, when general Cu + Zn plating is performed, Cu during plating plays a role of adhering rubber and reinforcing fiber when forming a reinforcing member. When the surface of the metal cord is not plated, the rubber and the reinforcing fiber are easily peeled off, and there is a concern that the progress of peeling easily occurs along the reinforcing fiber. Accordingly, in the present invention, when metal fibers are used as the reinforcing fibers, it is necessary to use plated ones, and even when a stranded wire cord is used as a raw material, single wires must be plated. is there. When the metal cord is made of a copper wire, the copper wire itself has an adhesive effect, so that plating is not necessary. In addition, in the case of non-metallic cords made of organic fibers, etc., by using an adhesive dipped in accordance with a conventional method, as with plated metal cords, adhesion to rubber is ensured. Is possible.

Here, the plating provided on the surface of the metal fiber as the reinforcing fiber is not particularly limited, and may be brass, bronze, Cu, Zn plating or the like. In particular, when the above-mentioned waste scraps are used as the reinforcing fibers, since these are already plated, there is an advantage that good adhesion to rubber can be obtained without further plating.

The rubber used for the reinforcing member can be appropriately selected from rubber types conventionally used for tire reinforcing member applications, and is not particularly limited. Further, the thickness of the reinforcing member itself is not particularly limited, and can be appropriately determined according to the target reinforcing performance, and can be, for example, 0.5 mm to 3.0 mm. This is because the thickness of the thinnest reinforcing member assumed when applied to a tire for a passenger car is 0.5 mm, while the thickness of the thickest reinforcing member assumed when applied to a heavy load tire is 3.0 mm. It means that there is.

The reinforcing member having a difference in basis weight as described above can be manufactured, for example, as follows. The reinforcing member manufacturing method and manufacturing apparatus will be described in detail later.
That is, first, a sheet of unvulcanized rubber having a predetermined thickness is prepared, and a bundle of reinforcing fiber pieces cut to a predetermined length is placed on the rubber sheet from a predetermined amount and a predetermined height on the rubber sheet. Is dropped to a uniform density. At this time, the guide body has a portion that opens in the vertical direction above the rubber sheet, has a width along the width direction of the rubber sheet that is wider at the lower end than the upper end, and gradually increases from the upper end toward the rubber sheet. The reinforcing fiber pieces are dropped on the rubber sheet through the guide body. As a result, the reinforcing fiber pieces fall on the rubber sheet so that the density decreases from the center in the width direction toward both outer sides, and thus the reinforcement having a difference in the basis density of the reinforcing fiber pieces in the width direction. A member can be obtained. Therefore, by cutting this reinforcing member at the center in the width direction, a reinforcing member having a predetermined fabric density gradient different between one end side and the other end side in the width direction can be applied to the present invention. It is obtained. This guide body also has an effect of preventing the density of the reinforced fiber pieces that are blown off from being dispersed more than necessary, and can be designed according to the width of the rubber sheet disposed below. Further, the difference in the basis weight density of the reinforcing fiber pieces can be adjusted by setting the dimensional shape of the guide body to a predetermined value.

Next, by covering an unvulcanized rubber sheet on the dropped reinforcing fiber piece, a reinforcing member in which the reinforcing fiber piece is embedded in rubber can be manufactured. At this time, by moving the lower rubber sheet at a predetermined speed in one direction, the density of the reinforcing fiber pieces in the reinforcing member is determined by the ratio between the amount of dropping of the reinforcing fiber pieces and the moving speed of the rubber sheet. be able to.

Here, as a method for dropping the predetermined amount of reinforcing fiber pieces, in addition to a method in which a bundle of reinforcing fiber pieces cut in advance is conveyed by a belt conveyor or the like and dropped onto a predetermined portion on a rubber sheet, there is no method. A method of dropping the cut reinforcing fiber pieces while cutting them may be used. In the latter case, it is not necessary to work to entangle the reinforcing fiber pieces or to supply a bundle of reinforcing fiber pieces at a constant amount in a certain amount of time, so that the reinforcing member can be manufactured more efficiently. Become.

Since the reinforcing member according to the present invention can be easily manufactured in one process as described above, it is easier to manufacture and consumes less energy than a conventional reinforcing member that requires a large number of steps for manufacturing. There is an advantage that the manufacturing cost is low.

In the tire of the present invention, it is important only that the reinforcing member is disposed so that the basis weight density of the reinforcing fiber pieces has a density gradient that becomes higher with respect to the bead portion side end portion at the tread portion side end portion, The other details of the tire structure and the material of each member are not particularly limited, and can be appropriately selected from conventionally known ones.

For example, the belt layer 3 is formed by rubberizing steel cords arranged in parallel at a predetermined angle with respect to the tire circumferential direction, and it is necessary to provide at least one layer. They are arranged in two layers. Further, as shown in the figure, the carcass is folded around the bead core 1 from the tire inner side to the outer side and locked. Further, the belt reinforcing layer 4 is composed of a rubberized layer of reinforcing cords arranged substantially parallel to the tire circumferential direction, and is arranged in a single sheet over the entire width of the belt layer 3 in the illustrated example. In the present invention, the present invention is not limited to this, and a pair of the belt layers 3 may be disposed in a region covering both ends of the belt layer 3. These may be arranged in combination, and the number of each belt reinforcing layer is not limited to the above.

Furthermore, a tread pattern (not shown) is appropriately formed on the surface of the tread portion 9, and an inner liner (not shown) is formed on the innermost layer. Furthermore, in the tire of the present invention, as the gas filled in the tire, normal or air having a changed oxygen partial pressure, or an inert gas such as nitrogen can be used.

Next, the first embodiment of the manufacturing method and the manufacturing apparatus of the reinforcing member of the present invention will be described in detail.
FIG. 6 is a partially cutaway front view showing an embodiment of the method and apparatus for manufacturing a reinforcing member of the present invention, and FIG. 7 is a cross-sectional view taken along the line II of FIG. In the present invention, a reinforcing fiber piece layer 13 composed of a plurality of reinforcing fiber pieces 12 obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of strip-shaped unvulcanized rubber sheets 11A and 11B as shown in FIG. The present invention relates to an improvement in technology when manufacturing the reinforcing member 10.

The reinforcing member 10 includes a belt-like rubber sheet 11A made of unvulcanized rubber, a belt-like rubber sheet 11B made of unvulcanized rubber superimposed on the rubber sheet 11A and pressure-bonded, and the rubber sheets 11A and 11B. It is formed from a reinforcing fiber piece layer 13 composed of a plurality of reinforcing fiber pieces 12 interposed therebetween. The rubber sheets 11A and 11B have the same width. The reinforcing fiber piece layer 13 has substantially the same width as that of the rubber sheets 11A and 11B, and extends in the longitudinal direction of the rubber sheets 11A and 11B. In this embodiment, as the rubber sheets 11A and 11B, rubber sheets whose temperature has been lowered to room temperature are used.

In the present embodiment, the rubber constituting the rubber sheets 11A and 11B can be appropriately selected from rubber types conventionally used for reinforcing member applications such as tires, and is particularly limited. is not. Specifically, for example, general-purpose rubbers such as styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR) can be used. The thickness of the rubber sheets 11A and 11B is not particularly limited and can be appropriately determined according to the target reinforcing performance, but is preferably in the range of 0.3 to 1.0 mm. When the thickness of the rubber sheets 11A and 11B is less than 0.3 mm, a part of the reinforcing fiber piece 12 may protrude from the outer surface of the reinforcing member 10 during vulcanization, while 1.0 mm is set. When it exceeds, there exists a possibility that a rubber gauge may become thick and the intensity | strength of a reinforcement member may fall.

Further, the reinforcing fiber piece layer 13 is formed into a layer shape by the plurality of reinforcing fiber pieces 12 being distributed substantially uniformly while intersecting at a plurality of positions. In the present embodiment, the reinforcing fiber pieces 12 in the reinforcing fiber piece layer 13 are not intertwined in a complicated manner like a nonwoven fabric, extend in a straight line, simply overlap each other, and are hardly intertwined. In the present embodiment, the reinforcing fiber piece 12 may extend in a curved shape such as an arc shape or an S shape. Further, these reinforcing fiber pieces 12 are randomly oriented (the extending direction is disordered), fall down on the rubber sheet 11A, and extend parallel to the upper surface thereof.

As a result, the reinforcing member 10 has substantially the same strength in any direction, and even when the reinforcing member 10 is cut and used, the reinforcing fiber piece has a very small cross-sectional area at the cut end. Since only a large number of the 12 cut surfaces are exposed, they do not become the core of crack generation. Furthermore, the strength of the reinforcing member 10 can be easily adjusted by adjusting the density (weight density) of the reinforcing fiber pieces 12 in the reinforcing fiber piece layer 13.

As described above, the vulcanized reinforcing member 10 can be suitably applied to a belt layer, a carcass layer, a wire chafer, a conveyor belt, a rubber crawler for a crawler vehicle, or the like constituting a pneumatic tire. In the present embodiment, the proportion of the reinforcing fiber pieces 12 extending in the width direction or the longitudinal direction of the rubber sheet may be increased by adjusting the orientation of some of the reinforcing fiber pieces 12, for example.

Here, the length (predetermined length) of the reinforcing fiber piece 12 after cutting is preferably within a range of 10 to 100 mm, and more preferably within a range of 30 to 60 mm. The diameter of the reinforcing fiber piece 12 is preferably in the range of 0.1 to 0.5 mm. Furthermore, when the reinforcing member 10 is used for the above-mentioned applications, the weight per unit area (mass per 1 m ² ) of the reinforcing fiber piece layer 13 is preferably 100 to 1000 g from the viewpoint of strength, rigidity, and the like. Preferably, it is within the range of 300 to 800 g.

In this embodiment, it is not necessary that all the reinforcing fiber pieces used for the reinforcing member have a single length and diameter, and a mixture of reinforcing fiber pieces having a plurality of types of lengths and diameters may be used. It is preferable to use a material having a length and diameter within the above range. In particular, if the length of the reinforcing fiber piece is too long, the uniformity of the reinforcing member is impaired. For example, when applied to a tire, the tire shape and the tire rigidity are uniform in the circumferential direction, which is a component that determines uniformity. It is not preferable from the point that property falls. In addition, the cross-sectional shape of the reinforcing fiber is basically circular, but a polygonal shape such as an ellipse or a triangle may be used.

In the present embodiment, any material may be used as the reinforcing fiber, and it can be appropriately selected from various materials usually used for reinforcing members such as tires. Specifically, for example, inorganic fibers include metal fibers such as steel filaments and glass fibers, and organic fibers include aromatic polyamide fibers, fatty acid polyamide fibers, polyester fibers, polyparaphenylenebenzeneoxazole fibers, and polyvinyl alcohol-based synthetics. Examples thereof include fibers and carbon fibers. In the present embodiment, among the above, it is preferable to use inorganic fibers, particularly steel filaments, as the reinforcing fibers.

Further, since the reinforcing fiber is embedded in rubber to form a reinforcing member, it is necessary to be plated or treated with an adhesive in order to ensure adhesion with the rubber. That is, in this embodiment, when the reinforcing fiber is a metal fiber, a plated one is used, and when the reinforcing fiber is an organic fiber, an adhesive-treated one is used. In a metal fiber such as a steel filament, for example, when general Cu + Zn plating is performed, Cu during plating plays a role of adhering rubber and reinforcing fiber when forming a reinforcing member. When the surface of the metal cord is not plated, the rubber and the reinforcing fiber are easily peeled off, and there is a concern that the progress of peeling easily occurs along the reinforcing fiber. Therefore, in this embodiment, when using a metal fiber as the reinforcing fiber, it is necessary to use a plated one, and even when a stranded wire cord is used as a raw material, the single wire needs to be plated. It is. When the metal cord is made of a copper wire, the copper wire itself has an adhesive effect, so that plating is not necessary. In addition, in the case of non-metallic cords made of organic fibers, etc., by using an adhesive dipped in accordance with a conventional method, as with plated metal cords, adhesion to rubber is ensured. Is possible.

Here, the plating provided on the surface of the metal fiber as the reinforcing fiber is not particularly limited, and may be brass, bronze, Cu, Zn plating or the like. If the outer surface of the reinforcing fiber piece 12 is plated, the coefficient of friction on the outer surface of the reinforcing fiber piece 12 becomes a very small value, so that it easily slips and flows.

The manufacturing apparatus shown in the figure has a fixed frame 22 that is fixed on the floor surface 21 and extends in the front-rear direction. A main conveyor 23 that extends in the front-rear direction is attached to the lower part of the fixed frame 22. The main conveyor 23 includes a pair of pulleys 24 rotatably supported at the front end and the rear end of the fixed frame 22, and a conveyor belt 25 that extends between the pair of pulleys 24 and extends in the front-rear direction. Yes. Here, a driving force is applied to one of the pair of pulleys 24 from a driving mechanism such as a motor (not shown). As a result, the transport unit 25a located on the upper side of the conveyor belt 25 can travel forward. When the conveyance unit 25a is traveling forward, when the rubber sheet 11A is supplied onto the conveyance unit 25a from the rear side by a supply unit (not shown), the rubber sheet 11A is supported from below by the conveyance unit 25a. It is conveyed toward the front.

In addition, a cutting means including an upper blade 28 and a lower blade 29 is attached to the upper end portion of the rear end portion of the fixed frame 22 via support portions 30 and 31. A transport unit 32 for transporting the reinforcing fibers 14 is disposed. Here, the reinforcing fiber 14 may be fed out and conveyed by a roller (not shown) on the conveyance unit 32 or may be conveyed using a conveyor similar to the main conveyor 23. The conveying section 32 and the rollers or conveyors as a whole constitute spraying means for spraying a plurality of reinforcing fiber pieces 12 on the rubber sheet 11A to form the reinforcing fiber piece layer 13.

The reinforcing fiber 14 mechanically conveyed forward on the conveying unit 32 is cut at the front end of the lower blade 29 by the upper blade 28 and the lower blade 29 to form a plurality of reinforcing fiber pieces 12 on the rubber sheet 11A. Fall. The front end of the lower blade 29 is located immediately above the rear end portion of the main conveyor 23. In this way, a cutting means for cutting the reinforcing fiber 14 into the reinforcing fiber piece 12 and a spreading means for spreading the cut reinforcing fiber piece 12 on the rubber sheet 11A are integrally provided, Since the cutting step and the spraying step are performed continuously, the reinforcing fiber pieces are not entangled with each other because the reinforcing fiber pieces are not cut in advance, and the need for opening is not generated. Further, if the reinforcing fibers 14 are unwound at a constant speed and cut at a constant speed, the cut reinforcing fiber pieces 12 can be obtained at a constant speed, so that a certain amount can be easily obtained at a constant time. The reinforcing fiber pieces 12 can be supplied. If the amount of cutting at one time is not large, the reinforcing fiber pieces are not entangled with each other, and it is not necessary to pass through a fiber opening machine. Therefore, if the reinforcing fiber 12 pieces cut at a constant speed are spread on the rubber sheet 11A as they are, the reinforcing member 10 having the random positions and the random orientation of the reinforcing fiber pieces 12 in the reinforcing fiber piece layer 13 is obtained. be able to.

Here, the amount of the reinforcing fiber pieces 12 produced by cutting, that is, the supply amount of the reinforcing fiber pieces 12 per unit time is adjusted to a predetermined value by setting the conveying speed of the reinforcing fibers 14. The number of the reinforcing fibers 14 to be conveyed can be a predetermined number based on the supply amount of the target reinforcing fiber pieces 12 and the width of the reinforcing fiber piece layer 13.

The reinforcing fiber pieces 12 dropped from the conveying unit 32 are dispersed (spread) on the rubber sheet 11A at the application position P of the reinforcing fiber pieces 12 with respect to the rubber sheet 11A. Since the dispersion of the reinforcing fiber pieces 12 and the conveyance of the rubber sheet 11A are continuously performed as described above, the reinforcement composed of the plurality of reinforcing fiber pieces 12 and extending in the longitudinal direction of the rubber sheet 11A is provided on the rubber sheet 11A. A fiber piece layer 13 is formed.

As described above, since the reinforcing fiber piece layer 13 is formed by previously spreading the plurality of reinforcing fiber pieces 12 on the rubber sheet 11A, the reinforcing fiber pieces 12 after the spreading are laid down by the flat rubber sheet 11A. Supported from below. As a result, the orientation direction (extending direction) of the reinforcing fiber pieces 12 can be easily randomized, and the distribution can be easily made uniform. Further, since the reinforcing member 10 can be manufactured simply by spreading the reinforcing fiber pieces 12, supplying the rubber sheet 11A, and pressing, the manufacturing cost of the apparatus can be reduced.

Here, if the ratio between the supply amount of the reinforcing fiber pieces 12 per unit time (conveying speed of the reinforcing fibers 14) and the running speed of the conveyor belt 25 in the main conveyor 23 is changed, the reinforcing fiber piece layer to be formed is changed. The basis weight of 13 can be easily adjusted. The supply amount of the reinforcing fiber pieces 12 per unit time is m (g / s), and the width (target width) of the reinforcing fiber piece layer 13 to be formed on the rubber sheet 11A is d (m). Assuming that the traveling speed is speed V (m / s), the basis weight ρ (weight per unit area (g / m ² )) of the reinforcing member 10 that can be manufactured by the present apparatus is represented by the following formula.
ρ = m / Vd

In the present embodiment, the rubber sheet 11A is placed on the support base and is stationary, while the spraying means installed above the rubber sheet 11A is moved in the longitudinal direction of the rubber sheet 11A by the spraying means. The reinforcing fiber pieces 12 may be dispersed on the rubber sheet 11A.

Reference numeral 46 denotes a guide body installed between the spraying means and the rubber sheet 11A. The guide body 46 is attached to the fixed frame 22 via an attachment plate 47. Here, the guide body 46 has a pair of wall portions 46a parallel to the longitudinal direction of the rubber sheet 11A, and the interval between the pair of wall portions 46a is formed narrower than the width of the rubber sheet 11A. Yes. By arranging such a guide body 46, the reinforcing fiber pieces 12 spread by the spreading means are supplied onto the rubber sheet 11A while being guided by the guide body 46, so that the rubber sheet of the reinforcing fiber pieces 12 is supplied. The scattering of 11A to the outside in the width direction is effectively prevented. However, in this case, since the scattering of the reinforcing fiber pieces 12 in the longitudinal direction of the rubber sheet 11A occurs slightly, portions where the density of the reinforcing fiber pieces 12 is low are formed in the spray start portion and the end portion. Therefore, more preferably, the guide body 46 further includes a pair of wall portions 46b parallel to the width direction of the rubber sheet 11A, and is open only in the vertical direction and has a passage having a rectangular cross section inside. Thereby, since it becomes possible to prevent scattering of the reinforcing fiber pieces 12 in the longitudinal direction of the rubber sheet 11A, scattering of the reinforcing fiber pieces 12 around the reinforcing fiber pieces 12 can be more effectively prevented. All the reinforcing fiber pieces 12 can be dispersed in the target range on the rubber sheet 11A. In addition, the shape of the channel | path inside the guide body in this case may be a cross-sectional circle other than a cross-sectional rectangle.

In addition, some of the reinforcing fiber pieces 12 collide with the guide body 46 during the fall, and the collision of the reinforcing fiber pieces 12 changes randomly due to the collision, and as a result, the reinforcing fiber pieces 12 become the rubber sheet. 11A is further uniformly distributed in a random orientation direction.

Here, when the guide body 46 is installed between the spraying means and the rubber sheet 11A, the distance h from the lower end of the guide body 46 to the surface of the rubber sheet 11A is five times the length of the reinforcing fiber piece 12. In the following, it is particularly preferably in the range of 1 to 3 times. When the height h of the guide body 46 is increased more than necessary, the reinforcing fiber pieces 12 are scattered around and it is difficult to accurately distribute the reinforcing fiber pieces 12 within the range of the target width d.

Further, in order to make the reinforcing fiber pieces 12 on the rubber sheet 11A more uniform and randomly oriented, for example, a plurality of baffle rods or baffles extending linearly or curvedly on the inner surface of the guide body 46 are used. A plate or the like may be attached so that the reinforcing fiber pieces 12 falling on the rubber sheet 11A from the spraying means collide with a baffle rod or the like, and more reinforcing fiber pieces 12 may be rebounded during the dropping. Furthermore, in the present embodiment, in order to adjust the basis weight of the reinforcing fiber piece layer 13, a generating means for generating a magnetic field or an electric field is installed in the guide body 46, or an adjusting plate in which a plurality of slits are formed. It can also be installed.

Reference numeral 50 is a support base attached to the upper end of the fixed frame 22 in front of the spraying means, and on this support base 50, a winding roll in which a long and continuous rubber sheet 11B is wound in a roll shape many times. 51 is rotatably supported. The rubber sheet 11 </ b> B unwound from the winding roll 51 is guided by a plurality of guide rollers 52 that are rotatably supported by the fixed frame 22 immediately below the winding roll 51, and is a supply position positioned forward from the spraying position P. D (supply position of rubber sheet 11B to rubber sheet 11A) is supplied from above, and is superimposed on rubber sheet 11A at supply position D. At this time, reinforcing fiber piece layer 13 is interposed between rubber sheets 11A and 11B. Be dressed.

The support base 50, the winding roll 51, and the guide roller 52 as a whole supply and superimpose the rubber sheet 11B on the rubber sheet 11A, and supply the reinforcing fiber piece layer 13 between the rubber sheets 11A and 11B. The means 53 is configured. In the present embodiment, an extruder or a calender roll device may be used as a supply means for supplying the rubber sheets 11A and 11B to the main conveyor 23. In this case, the rubber sheet 11A having a high temperature immediately after molding is used. , 11B are supplied to the main conveyor 23.

Reference numeral 56 is a pressure-bonding means installed immediately before the supply position D. The pressure-bonding means 56 has two pairs of upper and lower rollers 57 and 58 which are separated from each other in the vertical direction, and these two pairs of upper and lower rollers 57 and 58. Are arranged at a predetermined distance in the front-rear direction. Both ends of these two upper rollers 57 are rotatably supported by the fixed frame 22 and are in rolling contact with the upper surface of the rubber sheet 11B superimposed on the rubber sheet 11A. On the other hand, both of the two lower rollers 58 are supported by the fixed frame 22 so as to be freely rotatable, and are in rolling contact with the lower surface of the conveying portion 25a of the conveyor belt 25 in a pressed state.

Further, a driving force is applied to the upper roller 57 from a driving mechanism (not shown), whereby the upper roller 57 has the same traveling speed (conveying speed of the rubber sheet 11A and the like) as the peripheral speed. Drive and rotate. As a result, when the reinforcing fiber piece layer 13 and the rubber sheets 11A, 11B immediately after being overlapped pass between the two pairs of upper and lower rollers 57, 58, the rubber sheets 11A, 11B are interposed between the reinforcing fiber piece layers 13. In a worn state, they are pressed against each other and pressed, whereby the reinforcing member 10 is manufactured.

Here, the upper and lower rollers 57 and 58 are preferably heated to a temperature in the range of 50 to 100 ° C. The reason is that when the upper and lower rollers 57 and 58 are heated to this temperature range, the rubber of the rubber sheets 11A and 11B is plasticized without proceeding with the vulcanization of the rubber sheets 11A and 11B, and the gap between the reinforcing fiber pieces 12 is increased. This is because the rubber can be adhered to the entire outer surface of each reinforcing fiber piece 12. In the present embodiment, a bladder that expands or contracts by supplying or discharging a heating medium may be used as the crimping means. In this case, the rubber sheets 11A and 11B are connected to each other by the expansion of the bladder. Press and crimp.

Between the spraying position P and the supply position D, a rotatable entanglement roller 62 having a plurality of protrusions 61 on the outer periphery and parallel to the pulley 24 is disposed immediately above the rubber sheet 11A and the reinforcing fiber piece layer 13. ing. On the other hand, immediately below the entanglement roller 62, a support roller 63 is installed in parallel with the entanglement roller 62 and in rolling contact with the lower surface of the conveying portion 25a of the conveyor belt 25. The support roller 63 conveys the rubber sheet 11A. It is supported from below via the part 25a. Both ends of the entanglement roller 62 and the support roller 63 in the axial direction are rotatably supported by the fixed frame 22, but the entanglement roller 62 is given a driving force from a drive mechanism (not shown). The entanglement roller 62 is driven to rotate at the peripheral speed at the tip of the protrusion 61 at the same speed as the traveling speed of the conveyor belt 25.

When the entanglement roller 62 rotates in this way, the tip of the protrusion 61 pushes a part of the reinforcing fiber piece layer 13 conveyed by the main conveyor 23 toward the rubber sheet 11A, and a part of the reinforcing fiber pieces 12 is moved. By deforming, some of the reinforcing fiber pieces 12 are partially entangled with each other. As a result, even if the position of the reinforcing fiber piece 12 on the rubber sheet 11A is stable and the friction coefficient of the reinforcing fiber piece 12 is small as described above, the reinforcing fiber piece 12 moves from both ends of the rubber sheet 11A. Can be strongly suppressed from falling (sliding down). Here, the radial length of the protrusion 61 is preferably in the range of 1 to 100 mm.

Reference numeral 66 denotes a crushing roller installed between the spraying position P and the supply position D, here between the entanglement roller 62 and the supply position D. The crushing roller 66 is connected to the entanglement roller 62. While extending in parallel, both ends in the axial direction are rotatably supported by the fixed frame 22. A driving force is applied to the crushing roller 66 from the driving mechanism. As a result, the crushing roller 66 rotates at a peripheral speed on the outer surface thereof at the same speed as the traveling speed of the conveyor belt 25. it can. Further, a certain degree of unevenness is formed on the outer surface of the crushing roller 66 by knurling, shot blasting, or the like, thereby increasing the friction coefficient between the crushing roller 66 and the reinforcing fiber piece layer 13, Slip between them is suppressed.

On the other hand, immediately below the crushing roller 66, a support roller 67 is installed in parallel with the crushing roller 66 so as to be in rolling contact with the lower surface of the conveying portion 25a of the conveyor belt 25. The support roller 67 supports the rubber sheet 11 </ b> A from below via the transport unit 25 a, and both axial ends thereof are rotatably supported by the fixed frame 22. The crushing roller 66 presses the reinforcing fiber piece layer 13 against the rubber sheet 11A when the rubber sheet 11A and the reinforcing fiber piece layer 13 pass between the crushing roller 66 and the support roller 67, thereby reinforcing the reinforcing fiber piece layer. Crush 13 slightly in the thickness direction as a whole.

Thereby, the position of the reinforcing fiber piece 12 on the rubber sheet 11A is further stabilized. As a result, even if the friction coefficient of the reinforcing fiber piece 12 is small as described above, the reinforcing fiber piece 12 on the rubber sheet 11A is Movement, in particular, dropping from both side ends of the rubber sheet 11A can be strongly suppressed. In the present embodiment, the entanglement roller 62 may be installed in front of the crushing roller 66, contrary to the above.

Although not shown, in the present embodiment, it is preferable to further provide a vibration generating mechanism for vibrating the rubber sheet 11A. That is, it is preferable to arrange a vibration generator on the main conveyor 23 that conveys the rubber sheet 11A. The higher the density of the reinforcing fiber pieces 12 that have fallen on the rubber sheet 11A, the easier it is to form lumps with the surrounding reinforcing fiber pieces 12, and these lumps cause uneven density. In the present embodiment, a vibration generator is arranged on the main conveyor 23, the conveyor belt 25 is vibrated, and the rubber sheet 11A is vibrated in the spraying step, thereby eliminating the agglomeration of the reinforcing fiber pieces 12. Can do. The vibration generating mechanism can be disposed, for example, inside the conveyor belt 25, and the vibration direction can be the width direction of the rubber sheet 11A. The vibration frequency at this time is preferably in the range of 1 Hz to 1 kHz, more preferably 1 Hz to 1000 Hz, and further preferably 10 Hz to 100 Hz. When the vibration frequency is 1 Hz or less, the vibration energy is small and the reinforcing fiber piece 12 is difficult to move. On the other hand, if the vibration frequency is too high, the energy is too strong and the reinforcing fiber pieces 12 may be scattered around.

Next, the operation of this embodiment will be described.
In order to manufacture the reinforcing member 10 as described above, first, the reinforcing fiber 14 is sent out in the direction of the fixed frame 22 by the transport unit 32. At this time, the rubber sheet 11A is supplied to the main conveyor 23 from the rear side. The rubber sheet 11A supplied to the main conveyor 23 in this way travels forward from the conveyance unit 25a and is conveyed from below by the conveyance unit 25a. It is conveyed toward the front while being supported.

Here, the reinforcing fiber 14 is cut by the upper blade 28 and the lower blade 29 at the front end of the lower blade 29 to form a plurality of reinforcing fiber pieces 12, and falls onto the rubber sheet 11A. At this time, the supply amount of the reinforcing fiber pieces 12 per unit time is adjusted to a predetermined value by the conveyance speed of the reinforcing fibers 14. The dropped reinforcing fiber pieces 12 fall on the rubber sheet 11A, here spreading slightly to the spraying position P, and are sprayed uniformly and randomly. In this way, if the reinforcing fiber pieces 12 are spread on the rubber sheet 11A by dropping the reinforcing fiber pieces 12 from above the rubber sheet 11A, the reinforcing fiber pieces 12 can be easily and reliably attached to the rubber sheet 11A. Can be sprayed on top.

During the fall, the reinforcing fiber piece 12 is guided by the guide body 46, and scattering of the reinforcing fiber piece 12 to both sides is effectively prevented. In addition, some of the reinforcing fiber pieces 12 collide with the guide body 46 in the middle of dropping, and the reinforcing fiber pieces 12 jump around due to the collision, and the posture changes randomly. As a result, the reinforcing fiber pieces on the rubber sheet 11A 12, the distribution becomes more uniform and the orientation direction becomes further random. Furthermore, if vibration is given to the conveyor belt 25 to vibrate the rubber sheet 11A, the agglomeration of the reinforcing fiber pieces 12 can be more effectively suppressed. Since the dispersion of the reinforcing fiber pieces 12 and the conveyance of the rubber sheet 11A are continuously performed, the reinforcing fiber piece layer 13 composed of a plurality of reinforcing fiber pieces 12 extending in the longitudinal direction of the rubber sheet 11A on the rubber sheet 11A. Is formed.

Thereafter, the reinforcing fiber piece layer 13 is conveyed forward together with the rubber sheet 11A by running of the conveyor belt 25 and passes between the entanglement roller 62 and the support roller 63. At this time, the protrusion of the entanglement roller 62 The front end portion 61 pushes a part of the reinforcing fiber piece layer 13 toward the rubber sheet 11A, deforms some of the reinforcing fiber pieces 12, and partially entangles the reinforcing fiber pieces 12 with each other. The position of the reinforcing fiber piece 12 on 11A is stabilized.

Next, the rubber sheet 11A and the reinforcing fiber piece layer 13 are conveyed by the conveyor belt 25 and supplied to the crushing roller 66 and the support roller 67. The rubber sheet 11A and the support roller 67 are interposed between the rubber sheet 11A and the support roller 67. When the reinforcing fiber piece layer 13 passes, the crushing roller 66 presses the reinforcing fiber piece layer 13 against the rubber sheet 11A to slightly crush the reinforcing fiber piece layer 13 in the thickness direction as a whole, and on the rubber sheet 11A. The position of the reinforcing fiber piece 12 is further stabilized.

When the rubber sheet 11A and the reinforcing fiber piece layer 13 are conveyed to the supply position D by the conveyor belt 25, the rubber sheet 11B unwound from the winding roll 51 of the supply means 53 is supplied onto the rubber sheet 11A from above and overlapped. Thus, the reinforcing fiber piece layer 13 is interposed between the rubber sheets 11A and 11B. Thereafter, the rubber sheets 11 </ b> A and 11 </ b> B and the reinforcing fiber piece layer 13 are supplied to the upper and lower rollers 57 and 58 by the conveyor belt 25. When the rubber sheets 11A and 11B and the reinforcing fiber piece layer 13 pass between the upper and lower rollers 57 and 58, the rubber sheets 11A and 11B are pressed against each other with the reinforcing fiber piece layer 13 interposed between them and pressure bonded. Then, the reinforcing member 10 is manufactured.

At this time, since the upper and lower rollers 57 and 58 are heated to the above-described temperature range, the rubber of the rubber sheets 11A and 11B is plasticized and flows into the gap between the reinforcing fiber pieces 12, Rubber adheres to the entire surface. The reinforcing member 10 manufactured in this way is vulcanized and cut into a predetermined length and used for the above-described applications.

Next, a second embodiment of the method and apparatus for manufacturing a reinforcing member of the present invention will be described in detail.
9 is a partially cutaway front view showing another embodiment of the method and apparatus for manufacturing a reinforcing member of the present invention, and FIG. 10 is a cross-sectional view taken along the line II-II in FIG. In the present invention, a reinforcing fiber piece layer 113 composed of a plurality of reinforcing fiber pieces 112 obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of strip-like unvulcanized rubber sheets 111A and 111B as shown in FIG. The present invention relates to an improvement in technology when manufacturing the reinforcing member 110.

The reinforcing member 110 includes a belt-like rubber sheet 111A made of unvulcanized rubber, a belt-like rubber sheet 111B made of unvulcanized rubber superimposed on the rubber sheet 111A and pressure-bonded, and the rubber sheets 111A and 111B. It is formed from a reinforcing fiber piece layer 113 composed of a plurality of reinforcing fiber pieces 112 interposed therebetween. The rubber sheets 111A and 111B have the same width. The reinforcing fiber piece layer 113 has substantially the same width as that of the rubber sheets 111A and 111B, and is disposed so as to extend in the longitudinal direction of the rubber sheets 111A and 111B. Moreover, in this embodiment, the rubber sheet 111A, 111B is a rubber sheet whose temperature is lowered to room temperature.

In the present embodiment, the rubber constituting the rubber sheets 111A and 111B can be appropriately selected from rubber types conventionally used for reinforcing member applications such as tires, and is particularly limited. is not. Specifically, for example, a general-purpose rubber similar to that in the first embodiment can be used. The thicknesses of the rubber sheets 111A and 111B can be the same as in the first embodiment.

Further, the reinforcing fiber piece layer 113 is formed into a layer shape by a plurality of reinforcing fiber pieces 112 being substantially uniformly distributed while intersecting at a plurality of locations. In the present embodiment, the reinforcing fiber pieces 112 in the reinforcing fiber piece layer 113 are not intertwined in a complicated manner like a nonwoven fabric, extend in a straight line, simply overlap each other, and are hardly intertwined. In the present embodiment, the reinforcing fiber piece 112 may extend in a curved shape such as an arc shape or an S shape. In addition, these reinforcing fiber pieces 112 are randomly oriented (the extending direction is disordered), have different basis weights for each part, in the illustrated example, at a basis weight that gradually decreases from the top to the bottom in the figure, and It lies down on the rubber sheet 111A and extends parallel to the upper surface.

As a result, the reinforcing member 110 has the same strength in each direction in each part, but has a different strength for each part. Further, even when the reinforcing member 110 is cut and used, only a large number of cut surfaces of the reinforcing fiber pieces 112 having a very small cross-sectional area are exposed at the cut end of the reinforcing member 110. Also, it does not become the nucleus of crack generation. The strength of the reinforcing member 110 can be easily adjusted by adjusting the density (weight density) of the reinforcing fiber pieces 12 in the reinforcing fiber piece layer 113.

The vulcanized reinforcing member 110 can be suitably applied to a belt layer, a carcass layer, a wire chafer, a conveyor belt, a rubber crawler for a crawler vehicle, or the like constituting a pneumatic tire. In particular, the vulcanized reinforcing member 110 is preferably used as a side layer reinforcing layer in a pneumatic tire, and in a material stage before expansion, the bead portion side is low and the tread portion side is in a non-uniform state with high density. In this case, it is possible to prevent a decrease in density on the tread portion side after expansion. Further, for example, when it is desired to make the bead portion side of the reinforcing layer more dense, it is conceivable to assign a high-density portion of the reinforcing member to the bead portion side. In particular, in the case of a pneumatic tire for a passenger car, it is better that the reinforcement amount of the bead portion is larger in order to reinforce the carcass ply from the damage caused by the push-up from the rim flange. Here, if you only want to increase the density on the tread part side, you can also think of increasing the overall density with a uniform distribution, but in this case, an excessive amount of reinforcing fiber pieces will be scattered on the bead part. This is inefficient. In addition, when spraying more reinforcing fiber pieces than necessary, it can be said that it is not preferable because man-hours for wire cutting for that purpose cannot be ignored. In the present embodiment, the orientation of some of the reinforcing fiber pieces 112 may be adjusted, for example, to increase the ratio of the reinforcing fiber pieces 112 extending in the width direction or the longitudinal direction of the rubber sheet.

Here, the length (predetermined length) and diameter of the reinforcing fiber piece 112 after cutting and the basis weight of the reinforcing fiber piece layer 113 (mass per 1 m ² ) may be the same as those in the first embodiment. it can.

In this embodiment as well, as in the first embodiment, it is not necessary that all the reinforcing fiber pieces used for the reinforcing member have a single length and a diameter, but a plurality of types of lengths and diameters. The reinforcing fiber pieces may be mixed and used, but those having a length and a diameter within the above range are preferably used. In particular, if the length of the reinforcing fiber piece is too long, the uniformity of the reinforcing member is impaired. For example, when applied to a tire, the tire shape and the tire rigidity are uniform in the circumferential direction, which is a component that determines uniformity. It is not preferable from the point that property falls. In addition, the cross-sectional shape of the reinforcing fiber is basically circular, but a polygonal shape such as an ellipse or a triangle may be used.

In the present embodiment, any material may be used as the reinforcing fiber, and it can be appropriately selected from various materials usually used for reinforcing members such as tires. Specifically, for example, the same inorganic fibers and organic fibers as in the first embodiment can be mentioned, and among them, it is preferable to use inorganic fibers, particularly steel filaments.

Moreover, since the reinforcing fiber is embedded in rubber to form a reinforcing member, as in the first embodiment, plating or adhesive treatment is performed in order to ensure adhesion with rubber. It is necessary to be. The conditions relating to plating and adhesive treatment can be the same as those in the first embodiment, and are not particularly limited.

The illustrated manufacturing apparatus has a fixed frame 122 that is fixed on the floor 121 and extends in the front-rear direction, and a main conveyor 123 that extends in the front-rear direction is attached to the lower part of the fixed frame 122. The main conveyor 123 includes a pair of pulleys 124 rotatably supported at the front end and the rear end of the fixed frame 122, and a conveyor belt 125 that extends between the pair of pulleys 124 and extends in the front-rear direction. Yes. Here, a driving force is applied to one of the pair of pulleys 124 from a driving mechanism such as a motor (not shown). As a result, the transport unit 125a positioned on the upper side of the conveyor belt 125 can travel forward. When the rubber sheet 111A is supplied from the rear side to the conveying part 125a by a supply means (not shown) while the conveying part 125a is traveling forward, the rubber sheet 111A is supported from below by the conveying part 125a. It is conveyed toward the front.

In addition, a cutting means including an upper blade 128 and a lower blade 129 is attached to the upper end portion of the rear end portion of the fixed frame 122 via support portions 130 and 131. A transport unit 132 for transporting the reinforcing fibers 114 is disposed. Here, the reinforcing fibers 114 may be fed out and conveyed on the conveyance unit 132 by a roller (not shown), or may be conveyed using a conveyor similar to the main conveyor 123. The transport unit 132 and the rollers or conveyors as a whole constitute spraying means for spraying a plurality of reinforcing fiber pieces 112 on the rubber sheet 111A to form the reinforcing fiber piece layer 113.

The reinforcing fibers 114 mechanically conveyed forward on the conveying unit 132 are cut at the front end of the lower blade 129 by the upper blade 128 and the lower blade 129 to become a plurality of reinforcing fiber pieces 112, and on the rubber sheet 111A. Fall. The front end of the lower blade 129 is located immediately above the rear end portion of the main conveyor 123. In this way, a cutting means for cutting the reinforcing fiber 114 into the reinforcing fiber piece 112 and a spreading means for spreading the cut reinforcing fiber piece 112 on the rubber sheet 111A are integrally provided, Since the cutting step and the spraying step are performed continuously, the reinforcing fiber pieces are not entangled with each other because the reinforcing fiber pieces are not cut in advance, and the need for opening is not generated. Further, if the reinforcing fibers 114 are unwound at a constant speed and cut at a constant speed, the cut reinforcing fiber pieces 112 can be obtained at a constant speed, so that a certain amount can be easily obtained at a constant time. The reinforcing fiber pieces 112 can be supplied. If the amount of cutting at one time is not large, the reinforcing fiber pieces are not entangled with each other, and it is not necessary to pass through a fiber opening machine. Therefore, if the reinforcing fiber 112 pieces cut at a constant speed are spread on the rubber sheet 111A, the reinforcing member 110 having a uniform density in which the reinforcing fiber pieces 112 have a random orientation in the reinforcing fiber piece layer 113 is obtained. Can do.

Here, the amount of the reinforcing fiber pieces 112 produced by cutting, that is, the supply amount of the reinforcing fiber pieces 112 per unit time is adjusted to a predetermined value by setting the conveying speed of the reinforcing fibers 114. Further, the number of the reinforcing fibers 114 to be conveyed can be a predetermined number based on the supply amount of the target reinforcing fiber pieces 112 and the width of the reinforcing fiber piece layer 113.

The reinforcing fiber pieces 112 dropped from the conveying unit 132 are spread (spread) on the rubber sheet 111A at the spreading position P of the reinforcing fiber pieces 112 with respect to the rubber sheet 111A via a guide body 146 described later. Since the dispersion of the reinforcing fiber pieces 112 and the conveyance of the rubber sheet 111A are continuously performed as described above, the reinforcement formed of the plurality of reinforcing fiber pieces 112 on the rubber sheet 111A and extending in the longitudinal direction of the rubber sheet 111A. A fiber piece layer 113 is formed.

As described above, since the reinforcing fiber piece layer 113 is formed by previously spreading the plurality of reinforcing fiber pieces 112 on the rubber sheet 111A, the reinforcing fiber pieces 112 after the spreading are lying down by the flat rubber sheet 111A. Supported from below. As a result, the orientation direction (extending direction) of the reinforcing fiber pieces 112 can be easily randomized, and the distribution can be easily made uniform in the longitudinal direction of the rubber sheet 111A as described later. . Further, since the reinforcing member 110 can be manufactured simply by spreading the reinforcing fiber pieces 112, supplying the rubber sheet 111A, and pressing, the manufacturing cost of the apparatus can be reduced.

Here, if the ratio between the supply amount of the reinforcing fiber pieces 112 per unit time (the conveying speed of the reinforcing fibers 114) and the running speed of the conveyor belt 125 in the main conveyor 123 is changed, the reinforcing fiber piece layer to be formed The basis weight of 113 can be easily adjusted. The supply amount of the reinforcing fiber pieces 112 per unit time is m (g / s), and the width (target width) of the reinforcing fiber piece layer 113 to be formed on the rubber sheet 111A is d (m). Assuming that the traveling speed is a speed V (m / s), the basis weight ρ (weight per unit area (g / m ² )) of the reinforcing member 110 that can be manufactured by the present apparatus is represented by the following formula.
ρ = m / Vd

In the present embodiment, the rubber sheet 111A is placed on the support base and stopped, while the spraying means installed above the rubber sheet 111A is moved in the longitudinal direction of the rubber sheet 111A by the spraying means. The reinforcing fiber pieces 112 may be dispersed on the rubber sheet 111A.

Reference numeral 146 denotes a guide body installed between the spraying means and the rubber sheet 111 </ b> A. The guide body 146 is attached to the fixed frame 122 via a mounting plate 147. Here, the guide body 146 is opened only in the vertical direction, and has a passage inside. Further, the width of the guide body 146 along the width direction of the rubber sheet 111A is formed so as to have a portion that is wider at the lower end than the upper end and gradually increases from the upper side to the lower side. By arranging such a guide body 146, the reinforcing fiber pieces 112 spread by the spreading means are supplied onto the rubber sheet 111A while being guided by the guide body 146. Is effectively prevented. Further, since the width along the width direction of the rubber sheet 111A of the guide body 146 is wider at the lower end than the upper end and has a portion that gradually increases from the upper side to the lower side, the reinforcing fiber piece 112 is While the amount that falls directly below the cutting position is large, the amount that falls outside in the width direction of the rubber sheet 111A is smaller than the cutting position. As a result, all the reinforcing fiber pieces 112 can be dispersed in a target range on the rubber sheet 111A and from the center in the width direction of the rubber sheet 111A toward the outside so that the density decreases.

FIGS. 12A to 12C show variations of the guide body 146. FIG. In the present invention, the guide body 146 is opened only in the vertical direction, and the width along the width direction (lateral direction in the drawing) of the rubber sheet 111A is wider at the lower end than the upper end, and gradually increases from the upper side to the lower side. What is necessary is just to have a part to do. Reference numeral 146A is a portion where the width along the longitudinal direction of the rubber sheet 111A gradually increases from the upper side to the lower side (hereinafter referred to as a diameter-enlarged portion). A density distribution in which the density of the reinforcing fiber pieces 112 decreases toward the outside is formed. The shape of the enlarged diameter portion 146A may be bilaterally symmetric in the longitudinal direction of the rubber sheet 111A ((a) in the figure) or asymmetrical in the left and right ((b), ( c)), the outer shape of the cross section may be linear ((b) in the figure) or curved ((a) to (c) in the figure).

In the present invention, the density distribution of the reinforcing fiber pieces 112 can be controlled by adjusting the cross-sectional shape of the rubber sheet 111A in the width direction of the guide body 146. Here, the position where the effective width in which the reinforcing fiber pieces 112 are dispersed is d1, the width in the width direction of the rubber sheet 111A at the upper end in the guide body 146 is d2, and the width of the expanded diameter portion 146A is the effective distribution width d1. The height in the vertical direction is h1, and the height in the vertical direction from the position of the height h1 to the start position of the enlarged diameter portion 146A is h2. Since the width d1 is a width of the material determined based on the characteristic requirements of the tire, for example, for reinforcement, it is not basically changed. The ratio d1 / d2 is a parameter for changing the coarse density of the reinforcing fiber pieces 112. The height h2 is also a parameter for changing the coarse density. When the height h1 is large, the reinforcing fiber pieces 112 are less likely to be concentrated in the center in the width direction of the rubber sheet 111A, and the reinforcing fiber pieces 112 are likely to be scattered outside the width direction of the rubber sheet 111A beyond the effective width d1 (see FIG. 13 (a)). Further, when the height h2 is small, the reinforcing fiber pieces 112 are likely to be densely gathered at the center in the width direction of the rubber sheet 111A, and when the width d2 is small, the reinforcing fiber pieces 112 are likely to be densely gathered at the center in the width direction of the rubber sheet 111A ( (Refer FIG.13 (b)).

Note that some of the reinforcing fiber pieces 112 collide with the guide body 146 during the fall. However, due to this collision, the reinforcing fiber pieces 112 bouncing around and randomly change their postures. As a result, the reinforcing fiber pieces 112 are randomly In a uniform orientation and in the longitudinal direction of the rubber sheet 111A, it is more evenly dispersed.

Further, in order to make the reinforcing fiber pieces 112 on the rubber sheet 111A more uniform and random in the longitudinal direction, for example, a plurality of obstacles extending linearly or curvedly on the inner surface of the guide body 146 Attach a rod, baffle plate, etc. so that the reinforcing fiber piece 112 falling on the rubber sheet 111A from the spraying means collides with the baffle rod, etc., and more reinforcing fiber pieces 112 bounce around in the middle of dropping. Also good. Furthermore, in the present embodiment, in order to adjust the basis weight of the reinforcing fiber piece layer 113, a generating means for generating a magnetic field or an electric field is installed in the guide body 146, or an adjusting plate on which a plurality of slits are formed. It can also be installed.

Reference numeral 150 is a support base attached to the upper end of the fixed frame 122 in front of the spraying means, and a long and continuous rubber sheet 111B is wound around the support base 150 in a roll shape. 151 is rotatably supported. The rubber sheet 111 </ b> B unwound from the winding roll 151 is guided by a plurality of guide rollers 152 that are rotatably supported by the fixed frame 122 immediately below the winding roll 151, and is a supply position positioned in front of the spraying position P. D (supply position of the rubber sheet 111B to the rubber sheet 111A) is supplied from above, and is superimposed on the rubber sheet 111A at the supply position D. At this time, the reinforcing fiber piece layer 113 is interposed between the rubber sheets 111A and 111B. Be dressed.

The support base 150, the winding roll 151, and the guide roller 152 as a whole supply and superimpose a rubber sheet 111B on the rubber sheet 111A, and supply a reinforcing fiber piece layer 113 between the rubber sheets 111A and 111B. The means 153 is configured. In the present embodiment, an extruder or a calender roll device may be used as a supply means for supplying the rubber sheets 111A and 111B to the main conveyor 123. In this case, the rubber sheet 111A having a high temperature immediately after molding is used. , 111B is supplied to the main conveyor 123.

Reference numeral 156 is a pressure-bonding means installed immediately before the supply position D. The pressure-bonding means 156 has two pairs of an upper roller 157 and a lower roller 158 that are separated from each other in the vertical direction. Are arranged at a predetermined distance in the front-rear direction. Both ends of these two upper rollers 157 are rotatably supported by the fixed frame 122 and are in rolling contact with the upper surface of the rubber sheet 111B superimposed on the rubber sheet 111A. On the other hand, both ends of the two lower rollers 158 are supported by the fixed frame 122 so as to be freely rotatable, and are in rolling contact with the lower surface of the conveying portion 125a of the conveyor belt 125 in a pressed state.

Further, a driving force is applied to the upper roller 157 from a driving mechanism (not shown), whereby the upper roller 157 has the same traveling speed as the conveyor belt 125 (conveying speed of the rubber sheet 111A, etc.) and the peripheral speed. Drive and rotate. As a result, when the reinforcing fiber piece layer 113 and the rubber sheets 111A and 111B immediately after being overlapped pass between the two pairs of upper and lower rollers 157 and 158, the rubber sheets 111A and 111B are interposed between the reinforcing fiber piece layers 113. In a mounted state, they are pressed against each other and pressed, whereby the reinforcing member 110 is manufactured.

Here, the upper and lower rollers 157 and 158 are preferably heated to a temperature in the range of 50 to 100 ° C. The reason is that when the upper and lower rollers 157 and 158 are heated to this temperature range, the rubber of the rubber sheets 111A and 111B is plasticized without proceeding with the vulcanization of the rubber sheets 111A and 111B, and the gap between the reinforcing fiber pieces 112 is increased. This is because the rubber can be adhered to the entire outer surface of each reinforcing fiber piece 112. In the present embodiment, a bladder that expands or contracts by supplying or discharging a heating medium may be used as the crimping means. In this case, the rubber sheets 111A and 111B are bonded to each other by the expansion of the bladder. Press and crimp.

Between the spraying position P and the supply position D, a rotatable entanglement roller 162 having a plurality of protrusions 161 on the outer periphery parallel to the pulley 124 is disposed immediately above the rubber sheet 111A and the reinforcing fiber piece layer 113. ing. On the other hand, immediately below the entanglement roller 162, a support roller 163 that is in parallel with the entanglement roller 162 and is in rolling contact with the lower surface of the conveying portion 125a of the conveyor belt 125 is installed. The support roller 163 conveys the rubber sheet 111A. It supports from below via the part 125a. Both ends in the axial direction of the entanglement roller 162 and the support roller 163 are rotatably supported by the fixed frame 122, but the entanglement roller 162 is given a driving force from a drive mechanism (not shown). The entanglement roller 162 is driven and rotated at a peripheral speed at the tip of the protrusion 161 at the same speed as the traveling speed of the conveyor belt 125.

When the entanglement roller 162 rotates in this way, the tip of the protrusion 161 pushes a part of the reinforcing fiber piece layer 113 conveyed by the main conveyor 123 to the rubber sheet 111A side, and a part of the reinforcing fiber pieces 112 is pushed. By deforming, some of the reinforcing fiber pieces 112 are partially entangled with each other. As a result, even if the position of the reinforcing fiber piece 112 on the rubber sheet 111A is stable and the friction coefficient of the reinforcing fiber piece 112 is small as described above, the reinforcing fiber piece 112 moves from both side ends of the rubber sheet 111A. Can be strongly suppressed from falling (sliding down). Here, the radial length of the protrusion 161 is preferably in the range of 1 to 100 mm.

Reference numeral 166 denotes a crushing roller installed between the spraying position P and the supply position D, here between the entanglement roller 162 and the supply position D. The crushing roller 166 is connected to the entanglement roller 162. While extending in parallel, both ends in the axial direction are rotatably supported by the fixed frame 122. A driving force is applied to the crushing roller 166 from the driving mechanism. As a result, the crushing roller 166 can rotate at a peripheral speed on the outer surface thereof at the same speed as the traveling speed of the conveyor belt 125. it can. Further, a certain degree of irregularities are formed on the outer surface of the crushing roller 166 by knurling, shot blasting, or the like, thereby increasing the friction coefficient between the crushing roller 166 and the reinforcing fiber piece layer 113, Slip between them is suppressed.

On the other hand, a support roller 167 that is in rolling contact with the lower surface of the conveying portion 125a of the conveyor belt 125 is installed directly below the crushing roller 166 in parallel with the crushing roller 166. The support roller 167 supports the rubber sheet 111 </ b> A from below via the conveyance unit 125 a, and both end portions in the axial direction are rotatably supported by the fixed frame 122. This crushing roller 166 presses the reinforcing fiber piece layer 113 against the rubber sheet 111A when the rubber sheet 111A and the reinforcing fiber piece layer 113 pass between the crushing roller 166 and the support roller 167, and the reinforcing fiber piece layer Crush 113 slightly in the thickness direction as a whole.

As a result, the position of the reinforcing fiber piece 112 on the rubber sheet 111A is further stabilized. As a result, even if the friction coefficient of the reinforcing fiber piece 112 is small as described above, the reinforcing fiber piece 112 on the rubber sheet 111A is The movement, in particular, the fall from the both ends of the rubber sheet 111A can be strongly suppressed. In the present invention, the entanglement roller 162 may be installed in front of the crushing roller 166, contrary to the above.

The reinforcing member 110 obtained according to the present invention is cut into two at the center in the longitudinal direction to become a final material. That is, the reinforcing member 110 obtained as described above is directed from the center in the width direction to both outer sides, and the basis weight density of the reinforcing fiber pieces 112 is low. Thus, a material having an increased or decreased basis weight density can be obtained. Here, as a means for performing the cutting, the rubber sheets 111A and 111B can be pressed and pressed together with the reinforcing fiber piece layer 113 interposed therebetween, and then cut at the center in the width direction. If there is, there is no particular limitation. When a guide member 146 having an asymmetric shape as shown in FIG. 12C is used, a reinforcing member whose weight density increases or decreases from one end to the other end in the width direction is directly Since it is obtained, a cutting process becomes unnecessary.

Although not shown, in the present embodiment, it is preferable to further provide a vibration generating mechanism for vibrating the rubber sheet 111A. The conditions of this vibration generating mechanism can be the same as those in the first embodiment, and there is no particular limitation.

Next, the operation of this embodiment will be described.
In order to manufacture the reinforcing member 110 as described above, first, the reinforcing fiber 114 is sent out in the direction of the fixed frame 122 by the transport unit 132. At this time, the rubber sheet 111A is supplied to the main conveyor 123 from the rear side. However, the rubber sheet 111A supplied to the main conveyor 123 in this way travels forward from the conveying unit 125a and is conveyed from below by the conveying unit 125a. It is conveyed toward the front while being supported.

Here, the reinforcing fiber 114 is cut at the front end of the lower blade 129 by the upper blade 128 and the lower blade 129 to form a plurality of reinforcing fiber pieces 112 and falls onto the rubber sheet 111A. At this time, the supply amount of the reinforcing fiber pieces 112 per unit time is adjusted to a predetermined value by the conveyance speed of the reinforcing fibers 114. The dropped reinforcing fiber pieces 112 fall on the rubber sheet 111A, here at the spraying position P while spreading slightly in the longitudinal direction of the rubber sheet, and are sprayed uniformly and in a random orientation. In this way, if the reinforcing fiber pieces 112 are spread on the rubber sheet 111A by dropping the reinforcing fiber pieces 112 from above the rubber sheet 111A, the reinforcing fiber pieces 112 can be easily and reliably attached to the rubber sheet 111A. Can be sprayed on top.

During the fall, the reinforcing fiber pieces 112 are guided by the guide body 146, and scattering of the reinforcing fiber pieces 112 to both sides is effectively prevented. Further, the reinforcing fiber piece 112 is formed from the center in the width direction of the rubber sheet 111A by a portion (the enlarged diameter portion 146A) of the guide body 146 where the width along the width direction of the rubber sheet 111A gradually increases from the upper side to the lower side. It falls in a random orientation direction on the rubber sheet 111A in a density distribution such that the density decreases toward the outside. Furthermore, if vibration is applied to the conveyor belt 125 to vibrate the rubber sheet 111A, the agglomeration of the reinforcing fiber pieces 112 can be more effectively suppressed. Since the dispersion of the reinforcing fiber pieces 112 and the conveyance of the rubber sheet 111A are continuously performed, the reinforcing fiber piece layer 113 composed of a plurality of reinforcing fiber pieces 112 extending in the longitudinal direction of the rubber sheet 111A on the rubber sheet 111A. Is formed.

Thereafter, the reinforcing fiber piece layer 113 is conveyed forward together with the rubber sheet 111A by running of the conveyor belt 125 and passes between the entanglement roller 162 and the support roller 163. At this time, the protrusion of the entanglement roller 162 The front end portion 161 pushes a part of the reinforcing fiber piece layer 113 toward the rubber sheet 111A, deforms some of the reinforcing fiber pieces 112, and partially entangles the reinforcing fiber pieces 112 with each other. The position of the reinforcing fiber piece 112 on 111A is stabilized.

Next, the rubber sheet 111A and the reinforcing fiber piece layer 113 are conveyed by the conveyor belt 125 and supplied to the crushing roller 166 and the supporting roller 167. The rubber sheet 111A and the supporting roller 167 are interposed between the crushing roller 166 and the supporting roller 167. When the reinforcing fiber piece layer 113 passes, the crushing roller 166 presses the reinforcing fiber piece layer 113 against the rubber sheet 111A to slightly crush the reinforcing fiber piece layer 113 in the thickness direction as a whole, and on the rubber sheet 111A. The position of the reinforcing fiber piece 112 is further stabilized.

When the rubber sheet 111A and the reinforcing fiber piece layer 113 are conveyed to the supply position D by the conveyor belt 125, the rubber sheet 111B unwound from the winding roll 151 of the supply means 153 is supplied onto the rubber sheet 111A from above and overlapped. Thus, the reinforcing fiber piece layer 113 is interposed between the rubber sheets 111A and 111B. Thereafter, the rubber sheets 111A and 111B and the reinforcing fiber piece layer 113 are supplied to the upper and lower rollers 157 and 158 by the conveyor belt 125. When the rubber sheets 111A and 111B and the reinforcing fiber piece layer 113 pass between the upper and lower rollers 157 and 158, the rubber sheets 111A and 111B are pressed against each other with the reinforcing fiber piece layer 113 interposed between them and pressure bonded. Then, the reinforcing member 110 is manufactured. The reinforcing member 110 is further cut at the center in the longitudinal direction to obtain a final reinforcing material in which the basis density increases or decreases from one end to the other end in the width direction.

At this time, since the upper and lower rollers 157 and 158 are heated to the above-described temperature range, the rubber of the rubber sheets 111A and 111B is plasticized and flows into the gap between the reinforcing fiber pieces 112, and the outer sides of the reinforcing fiber pieces 112 are removed. Rubber adheres to the entire surface. The reinforcing member 110 manufactured in this way is vulcanized and cut into a predetermined length, and is used for the above-described applications.

Next, the third embodiment of the manufacturing method and the manufacturing apparatus of the reinforcing member of the present invention will be described in detail.
FIG. 14 is a partially cutaway front view showing still another embodiment of the reinforcing member manufacturing method and manufacturing apparatus of the present invention, and FIG. 15 is a cross-sectional view taken along line III-III in FIG. In the present invention, a reinforcing fiber piece layer 213 composed of a plurality of reinforcing fiber pieces 212 obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of strip-like unvulcanized rubber sheets 211A and 211B as shown in FIG. The present invention relates to an improvement in technology when manufacturing the reinforcing member 210.

The reinforcing member 210 includes a belt-like rubber sheet 211A made of unvulcanized rubber, a belt-like rubber sheet 211B made of unvulcanized rubber superimposed on the rubber sheet 211A and press-bonded, and these rubber sheets 211A and 211B. It is formed from a reinforcing fiber piece layer 213 composed of a plurality of reinforcing fiber pieces 212 interposed therebetween. The rubber sheets 211A and 211B have the same width. Further, the reinforcing fiber piece layer 213 has substantially the same width as the rubber sheets 211A and 211B, and is disposed so as to extend in the longitudinal direction of the rubber sheets 211A and 211B. Moreover, in this embodiment, the rubber sheet 211A, 211B uses a rubber sheet whose temperature has dropped to room temperature.

In the present embodiment, the rubber constituting the rubber sheets 211A and 211B can be appropriately selected from rubber types conventionally used for reinforcing member applications such as tires, and is particularly limited. is not. Specifically, for example, a general-purpose rubber similar to that in the first embodiment can be used. Further, the thicknesses of the rubber sheets 211A and 211B can be the same as those in the first embodiment, and are not particularly limited.

Further, the reinforcing fiber piece layer 213 has a layer shape in which a plurality of reinforcing fiber pieces 212 are distributed substantially uniformly while intersecting at a plurality of locations. In the present embodiment, the reinforcing fiber pieces 212 in the reinforcing fiber piece layer 213 are not intertwined in a complicated manner like a non-woven fabric, extend in a straight line, and simply overlap each other, and are hardly intertwined. In the present embodiment, the reinforcing fiber piece 212 may extend in a curved shape such as an arc shape or an S shape. In addition, as shown in the drawing, these reinforcing fiber pieces 212 are substantially oriented in one direction, fall down on the rubber sheet 211A, and extend parallel to the upper surface thereof.

As a result, the reinforcing member 210 is suitable for reinforcement in a specific direction. Even when the reinforcing member 210 is cut and used, a reinforcing fiber piece having a very small cross-sectional area is formed at the cut end of the reinforcing member 210. Since only a large number of the cut surfaces 212 are exposed, it does not become a nucleus of crack generation. The strength of the reinforcing member 210 can be easily adjusted by adjusting the density (weight density) of the reinforcing fiber pieces 212 in the reinforcing fiber piece layer 213.

The vulcanized reinforcing member 210 can be suitably applied to a belt layer, a carcass layer, a wire chafer, a conveyor belt, a rubber crawler for a crawler vehicle, etc. that constitute a pneumatic tire.

Here, the length (predetermined length) of the reinforcing fiber piece 212 after cutting, the diameter, and the basis weight (mass per 1 m ² ) of the reinforcing fiber piece layer 213 may be the same as those in the first embodiment. There is no particular limitation.

In this embodiment as well, as in the first embodiment, it is not necessary that all the reinforcing fiber pieces used for the reinforcing member have a single length and a diameter, but a plurality of types of lengths and diameters. The reinforcing fiber pieces may be mixed and used, but those having a length and a diameter within the above range are preferably used. In particular, if the length of the reinforcing fiber piece is too long, the uniformity of the reinforcing member is impaired. For example, when applied to a tire, the tire shape and the tire rigidity are uniform in the circumferential direction, which is a component that determines uniformity. It is not preferable from the point that property falls. In addition, the cross-sectional shape of the reinforcing fiber is basically circular, but a polygonal shape such as an ellipse or a triangle may be used.

In the present embodiment, any material may be used as the reinforcing fiber, and it can be appropriately selected from various materials usually used for reinforcing members such as tires. Specifically, for example, the same inorganic fibers and organic fibers as in the first embodiment can be mentioned, and among them, it is preferable to use inorganic fibers, particularly steel filaments.

Moreover, since the reinforcing fiber is embedded in rubber to form a reinforcing member, as in the first embodiment, plating or adhesive treatment is performed in order to ensure adhesion with rubber. It is necessary to be. The conditions for plating and adhesive treatment can be the same as those in the first embodiment, and are not particularly limited.

The illustrated manufacturing apparatus has a fixed frame 222 that is fixed on the floor surface 221 and extends in the front-rear direction, and a main conveyor 223 that extends in the front-rear direction is attached to the lower portion of the fixed frame 222. The main conveyor 223 includes a pair of pulleys 224 rotatably supported on the front end and the rear end of the fixed frame 222, and a conveyor belt 225 that extends between the pair of pulleys 224 and extends in the front-rear direction. Yes. Here, a driving force is applied to one of the pair of pulleys 224 from a driving mechanism such as a motor (not shown). As a result, the transport unit 225a located on the upper side of the conveyor belt 225 can travel forward. When the conveyance unit 225a is traveling forward, if the rubber sheet 211A is supplied onto the conveyance unit 225a from the rear side by a supply unit (not shown), the rubber sheet 211A is supported from below by the conveyance unit 225a. It is conveyed toward the front.

Further, cutting means comprising an upper blade 228 and a lower blade 229 is attached to the upper end portion of the rear end portion of the fixed frame 222 via support portions 230 and 231. A transport unit 232 for transporting the reinforcing fibers 214 is disposed. Here, the reinforcing fibers 214 may be fed out and conveyed by a roller (not shown) on the conveyance unit 232 or may be conveyed using a conveyor similar to the main conveyor 223. The transport unit 232 and the rollers or conveyors as a whole constitute spraying means for spraying a plurality of reinforcing fiber pieces 212 onto the rubber sheet 211A to form the reinforcing fiber piece layer 213.

The reinforcing fibers 214 mechanically conveyed forward on the conveying unit 232 are cut at the front end of the lower blade 229 by the upper blade 228 and the lower blade 229 to form a plurality of reinforcing fiber pieces 212 on the rubber sheet 211A. Fall. The front end of the lower blade 229 is located immediately above the rear end portion of the main conveyor 223. In this way, a cutting means for cutting the reinforcing fiber 214 into the reinforcing fiber piece 212 and a spreading means for spreading the cut reinforcing fiber piece 212 on the rubber sheet 211A are integrally provided, Since the cutting step and the spraying step are performed continuously, the reinforcing fiber pieces are not entangled with each other because the reinforcing fiber pieces are not cut in advance, and the need for opening is not generated. Further, if the reinforcing fiber 214 is unwound at a constant speed and cut at a constant speed, the cut reinforcing fiber piece 212 can be obtained at a constant speed, so that a certain amount can be easily obtained at a constant time. The reinforcing fiber piece 212 can be supplied. If the amount of cutting at one time is not large, the reinforcing fiber pieces are not entangled with each other, and it is not necessary to pass through a fiber opening machine. Therefore, if the reinforcing fiber 212 pieces cut at a constant speed are spread on the rubber sheet 211A, the reinforcing member 210 having a uniform density can be easily obtained.

Here, the amount of the reinforcing fiber piece 212 produced by cutting, that is, the supply amount of the reinforcing fiber piece 212 per unit time is adjusted to a predetermined value by setting the conveying speed of the reinforcing fiber 214. Further, the number of the reinforcing fibers 214 to be conveyed can be a predetermined number based on the supply amount of the target reinforcing fiber pieces 212 and the width of the reinforcing fiber piece layer 213.

The reinforcing fiber pieces 212 dropped from the conveying unit 232 are spread (spread) on the rubber sheet 211A at the spreading position P of the reinforcing fiber pieces 212 with respect to the rubber sheet 211A via a guide body 246 described later. Since the dispersion of the reinforcing fiber pieces 212 and the conveyance of the rubber sheet 211A are continuously performed as described above, the reinforcement composed of the plurality of reinforcing fiber pieces 12 and extending in the longitudinal direction of the rubber sheet 211A is provided on the rubber sheet 211A. A fiber piece layer 213 is formed.

As described above, since the reinforcing fiber piece layer 213 is formed by spreading a plurality of reinforcing fiber pieces 212 in advance on the rubber sheet 211A, the reinforcing fiber piece 212 after spreading is laid down by the flat rubber sheet 211A. Supported from below. As a result, the distribution of the reinforcing fiber pieces 212 can be easily made uniform. Further, since the reinforcing member 210 can be manufactured simply by spreading the reinforcing fiber pieces 212, supplying the rubber sheet 211A, and pressing, the manufacturing cost of the apparatus can be reduced.

Here, if the ratio between the supply amount of the reinforcing fiber pieces 212 per unit time (conveying speed of the reinforcing fibers 214) and the traveling speed of the conveyor belt 225 in the main conveyor 223 is changed, the reinforcing fiber piece layer to be formed is changed. The basis weight of 213 can be easily adjusted. The supply amount of the reinforcing fiber piece 212 per unit time is m (g / s), the width (target width) of the reinforcing fiber piece layer 213 to be formed on the rubber sheet 211A is d (m), and the conveyor belt 225 Assuming that the traveling speed is a speed V (m / s), the basis weight ρ (weight per unit area (g / m ² )) of the reinforcing member 210 that can be manufactured by the present apparatus is represented by the following formula.
ρ = m / Vd

In the present embodiment, the rubber sheet 211A is placed on the support base and stopped, while the spraying means installed above the rubber sheet 211A is moved in the longitudinal direction of the rubber sheet 211A by the spraying means. The reinforcing fiber pieces 212 may be dispersed on the rubber sheet 211A.

Reference numeral 246 denotes a guide body installed between the spraying means and the rubber sheet 211A. The guide body 246 is attached to the fixed frame 222 via a mounting plate 247. Here, the guide body 246 is narrower than at least the rubber sheet 211A, opens only in the vertical direction, and has a passage inside. Further, the width of the guide body 246 along the longitudinal direction of the rubber sheet 211A is formed so as to have a narrowed portion 246A that is narrower at the lower end than the upper end and gradually decreases from the upper side to the lower side. By arranging such a guide body 246, the reinforcing fiber pieces 212 spread by the spreading means are supplied onto the rubber sheet 211A while being guided by the guide bodies 246. Is effectively prevented. Further, the guide body 246 has a narrowed portion 246A in which the width along the longitudinal direction of the rubber sheet 211A is narrower at the lower end than the upper end, and the width gradually decreases from the upper side to the lower side. The fiber pieces 212 are prevented from facing in the direction along the longitudinal direction of the rubber sheet 211A, and the reinforcing fiber pieces 212 are oriented in the width direction of the rubber sheet 211A. Thereby, it becomes possible to disperse all the reinforcing fiber pieces 212 in a predetermined orientation direction within a target range on the rubber sheet 211A.

FIGS. 17A to 17C show variations of the guide body 246. FIG. In the present invention, the guide body 246 is opened only in the vertical direction, the width along the longitudinal direction (lateral direction in the drawing) of the rubber sheet 211A is narrower at the lower end than the upper end, and gradually decreases from the upper side to the lower side. It is sufficient if it has a throttle part to be used. The orientation direction of the reinforcing fiber pieces 212 is aligned with the width direction of the rubber sheet 211A by the narrowed portion 246A in which the width along the longitudinal direction of the rubber sheet 211A gradually decreases from the spreading means side toward the rubber sheet 211A side. As shown in the figure, the shape of the narrowed portion 246A may be bilaterally symmetric in the longitudinal direction of the rubber sheet 211A ((a) in the figure) or asymmetrical in the left and right ((b), (c) in the figure. )), And the outer shape of the cross section may be linear ((a), (b) in the figure) or curved ((c) in the figure). Further, the inclination angle θ of the narrowed portion 246A is not particularly limited, but if the inclined angle θ is too small, the reinforcing fiber pieces 212 are deposited on the upper portion of the narrowed portion 246A, so θ is 5 ° or more. It is preferable.

Further, as shown in the drawing, the guide body 246 preferably has a vertical portion 246B below the throttle portion 246A, where the width along the longitudinal direction of the rubber sheet 211A does not vary. By providing the vertical portion 246B on the rubber sheet 211A side from the narrowed portion 246A, the orientation direction of the reinforcing fiber pieces 212 aligned in the width direction of the rubber sheet 211A is narrowed, and the rubber sheet is maintained in this state. 211A can be dropped. If the vertical portion 246B is not provided, the direction of the reinforcing fiber piece 212 may be disturbed and fall as shown in FIG.

The width d of the lower end portion of the guide body 246 in the longitudinal direction of the rubber sheet 211A is preferably 1.0 times or less, particularly 0.5 to 0.8 times the length of the reinforcing fiber piece 212. If the width d of the guide body 246 is too wide, the degree of freedom of movement of the reinforcing fiber piece 212 in the longitudinal direction of the rubber sheet 211A increases, and thus it is difficult to limit the orientation direction. The preferable range of the width d of the guide body 246 varies depending on the length of the reinforcing fiber piece 212.

The distance h1 from the lower end of the guide body 246 to the rubber sheet 211A is preferably 1.0 times or less, particularly 0.5 to 0.9 times the length of the reinforcing fiber piece 212. When the reinforcing fiber piece 212 falls, it jumps in a random direction. At this time, if the distance h1 is too large, it becomes difficult to limit the direction of the jumping reinforcing fiber piece 212. Therefore, it is preferable not to make the distance h1 larger than necessary. The preferred range of the distance h1 also varies depending on the length of the reinforcing fiber piece 212.

Furthermore, the length h2 of the vertical portion 246B is preferably 0.8 times or more, particularly 1.0 to 1.5 times the length of the reinforcing fiber piece 212. As described above, the provision of the vertical portion 246B is important for restricting the orientation direction of the reinforcing fiber 212. When the vertical portion 246B is provided, it is desirable that the length is a certain length, but on the other hand, When the length h2 of the portion 246B is increased, the potential energy when the reinforcing fiber piece 212 is dropped increases, and the force that jumps when the reinforcing fiber piece 212 falls on the surface of the rubber sheet 211A also increases. From these viewpoints, the length h2 of the vertical portion 246B is preferably within the above range. The preferred range of the distance h2 also varies depending on the length of the reinforcing fiber piece 212.

Further, in the present invention, in order to adjust the basis weight of the reinforcing fiber piece layer 213, a generating means for generating a magnetic field or an electric field is installed in the guide body 246, or an adjusting plate having a plurality of slits is installed. You can also

Reference numeral 250 is a support base attached to the upper end of the fixed frame 222 in front of the spraying means, and a long and continuous rubber sheet 211B is wound on the support base 250 in a roll shape many times. 251 is rotatably supported. The rubber sheet 211 </ b> B unwound from the winding roll 251 is guided by a plurality of guide rollers 252 that are rotatably supported by the fixed frame 222 immediately below the winding roll 251, and a supply position that is positioned in front of the spraying position P. D (supply position of the rubber sheet 211B to the rubber sheet 211A) is supplied from above, and is superimposed on the rubber sheet 211A at the supply position D. At this time, the reinforcing fiber piece layer 213 is interposed between the rubber sheets 211A and 211B. Be dressed.

The support base 250, the winding roll 251 and the guide roller 252 as a whole supply and superimpose a rubber sheet 211B on the rubber sheet 211A and supply a reinforcing fiber piece layer 213 between the rubber sheets 211A and 211B. The means 253 is configured. In this embodiment, an extruder or a calender roll device may be used as a supply means for supplying the rubber sheets 211A and 211B to the main conveyor 223. In this case, the rubber sheet 211A having a high temperature immediately after molding is used. , 211B are supplied to the main conveyor 223.

Reference numeral 256 denotes a pressure-bonding means installed immediately before the supply position D. The pressure-bonding means 256 has two pairs of an upper roller 257 and a lower roller 258 that are vertically separated, and these two pairs of upper and lower rollers 257, 258. Are arranged at a predetermined distance in the front-rear direction. Both ends of these two upper rollers 257 are rotatably supported by the fixed frame 222, and are in rolling contact with the upper surface of the rubber sheet 211B superimposed on the rubber sheet 211A. On the other hand, both ends of the two lower rollers 258 are supported by the fixed frame 222 so as to be free to rotate, and are in rolling contact with the lower surface of the transport unit 225a of the conveyor belt 225.

Further, a driving force is applied to the upper roller 257 from a driving mechanism (not shown), whereby the upper roller 257 has a traveling speed of the conveyor belt 225 (conveying speed of the rubber sheet 211A, etc.) and a peripheral speed at the same speed. Drive and rotate. As a result, when the reinforcing fiber piece layer 213 and the rubber sheets 211A and 211B immediately after being overlapped pass between the two pairs of upper and lower rollers 257 and 258, the rubber sheets 211A and 211B are interposed between the reinforcing fiber piece layers 213. In a mounted state, they are pressed against each other and pressed, whereby the reinforcing member 210 is manufactured.

Here, the upper and lower rollers 257 and 258 are preferably heated to a temperature in the range of 50 to 100 ° C. The reason is that when the upper and lower rollers 257 and 258 are heated to this temperature range, the rubber of the rubber sheets 211A and 211B is plasticized without proceeding with the vulcanization of the rubber sheets 211A and 211B, and the gap between the reinforcing fiber pieces 212 is increased. This is because the rubber can be adhered to the entire outer surface of each reinforcing fiber piece 212. In the present invention, a bladder that expands or contracts by supplying or discharging a heating medium may be used as the crimping means. In this case, the rubber sheets 211A and 211B are pressed against each other by the expansion of the bladder. And crimp.

Between the spraying position P and the supply position D, a rotatable entanglement roller 262 having a plurality of protrusions 261 on the outer periphery and parallel to the pulley 224 is disposed immediately above the rubber sheet 211A and the reinforcing fiber piece layer 213. ing. On the other hand, immediately below the entanglement roller 262, a support roller 263 that is parallel to the entanglement roller 262 and is in rolling contact with the lower surface of the conveyor unit 225a of the conveyor belt 225 is installed. The support roller 263 conveys the rubber sheet 211A. It is supported from below via the part 225a. Both ends of the entanglement roller 262 and the support roller 263 in the axial direction are rotatably supported by the fixed frame 222, but the entanglement roller 262 is given a driving force from a drive mechanism (not shown). The entanglement roller 262 is driven and rotated at a peripheral speed at the tip of the protrusion 261 at the same speed as the traveling speed of the conveyor belt 225.

When the entanglement roller 262 rotates in this way, the tip portion of the protrusion 261 pushes a part of the reinforcing fiber piece layer 213 conveyed by the main conveyor 223 toward the rubber sheet 211A, so that a part of the reinforcing fiber pieces 212 is moved. By deforming, some of the reinforcing fiber pieces 212 are partially entangled with each other. As a result, even if the position of the reinforcing fiber piece 212 on the rubber sheet 211A is stable and the friction coefficient of the reinforcing fiber piece 212 is small as described above, the reinforcing fiber piece 212 moves from both ends of the rubber sheet 211A. Can be strongly suppressed from falling (sliding down). Here, the radial length of the protrusion 261 is preferably in the range of 1 to 100 mm.

Reference numeral 266 denotes a crushing roller installed between the spraying position P and the supply position D, here between the entanglement roller 262 and the supply position D. The crushing roller 266 is connected to the entanglement roller 262. Both ends in the axial direction extend in parallel and are rotatably supported by the fixed frame 222. A driving force is applied to the crushing roller 266 from the driving mechanism. As a result, the crushing roller 266 can rotate at a peripheral speed on the outer surface thereof at the same speed as the traveling speed of the conveyor belt 225. it can. Further, a certain degree of irregularities are formed on the outer surface of the crushing roller 266 by knurling, shot blasting, etc., thereby increasing the friction coefficient between the crushing roller 266 and the reinforcing fiber piece layer 213, Slip between them is suppressed.

On the other hand, immediately below the crushing roller 266, a support roller 267 is provided in parallel with the crushing roller 266 so as to be in rolling contact with the lower surface of the conveying unit 225a of the conveyor belt 225. The support roller 267 supports the rubber sheet 211A from below via the conveyance unit 225a, and both axial ends thereof are rotatably supported by the fixed frame 222. The crushing roller 266 presses the reinforcing fiber piece layer 213 against the rubber sheet 211A when the rubber sheet 211A and the reinforcing fiber piece layer 213 pass between the crushing roller 266 and the support roller 267, thereby reinforcing the reinforcing fiber piece layer. Crush 213 slightly in the thickness direction as a whole.

Thereby, the position of the reinforcing fiber piece 212 on the rubber sheet 211A is further stabilized. As a result, even if the friction coefficient of the reinforcing fiber piece 12 is small as described above, the reinforcing fiber piece 212 on the rubber sheet 211A has a small coefficient of friction. Movement, in particular, dropping from the both side ends of the rubber sheet 211A can be strongly suppressed. In the present invention, the entanglement roller 262 may be installed in front of the crushing roller 266 in the opposite manner.

Although not shown, in the present embodiment, it is preferable to further provide a vibration generating mechanism for vibrating the rubber sheet 211A. The conditions of the vibration generating mechanism can be the same as those in the first embodiment, and are not particularly limited.

Next, the operation of this embodiment will be described.
To manufacture the reinforcing member 210 as described above, first, the reinforcing fiber 214 is sent out in the direction of the fixed frame 222 by the transport unit 232. At this time, the rubber sheet 211A is supplied to the main conveyor 223 from the rear side. The rubber sheet 211A supplied to the main conveyor 223 in this way travels forward from the conveyance unit 225a, and is conveyed from below by the conveyance unit 225a. It is conveyed toward the front while being supported.

Here, the reinforcing fiber 214 is cut by the upper blade 228 and the lower blade 229 at the front end of the lower blade 229 to form a plurality of reinforcing fiber pieces 212 and falls onto the rubber sheet 211A. At this time, the supply amount of the reinforcing fiber piece 212 per unit time is adjusted to a predetermined value by the conveyance speed of the reinforcing fiber 214. The dropped reinforcing fiber pieces 212 fall on the rubber sheet 211A, here at the spraying position P, slightly spreading in the width direction of the rubber sheet, and sprayed uniformly. In this way, if the reinforcing fiber pieces 212 are sprayed onto the rubber sheet 211A by dropping the reinforcing fiber pieces 212 from above the rubber sheet 211A, the reinforcing fiber pieces 212 can be easily and reliably attached to the rubber sheet 211A. Can be sprayed on top.

During the fall, the reinforcing fiber piece 212 is guided by the guide body 246, and scattering of the reinforcing fiber piece 212 to both sides is effectively prevented. Further, the reinforcing fiber piece 212 has a guide body 246 whose rubber is aligned in the orientation direction by the narrowed portion 246A in which the width along the longitudinal direction of the rubber sheet 211A gradually decreases from the upper side to the lower side, and further the vertical portion 246B thereafter. The sheet 211A is aligned and squeezed in the width direction, and uniformly falls on the rubber sheet 211A in a fixed orientation direction. Furthermore, if vibration is given to the conveyor belt 225 to vibrate the rubber sheet 211A, the agglomeration of the reinforcing fiber pieces 212 can be more effectively suppressed. Since the dispersion of the reinforcing fiber pieces 212 and the conveyance of the rubber sheet 211A are continuously performed, the reinforcing fiber piece layer 213 configured with a plurality of reinforcing fiber pieces 212 extending in the longitudinal direction of the rubber sheet 211A on the rubber sheet 211A. Is formed.

Thereafter, the reinforcing fiber piece layer 213 is transported forward together with the rubber sheet 211A by running of the conveyor belt 225 and passes between the entanglement roller 262 and the support roller 263. At this time, the protrusion of the entanglement roller 262 The tip of 261 pushes a part of the reinforcing fiber piece layer 213 toward the rubber sheet 211A, deforms some of the reinforcing fiber pieces 212, and partially entangles the reinforcing fiber pieces 212 with each other. The position of the reinforcing fiber piece 212 on 211A is stabilized.

Next, the rubber sheet 211A and the reinforcing fiber piece layer 213 are conveyed by the conveyor belt 225 and supplied to the crushing roller 266 and the supporting roller 267. The rubber sheet 211A and the supporting roller 267 are interposed between the crushing roller 266 and the supporting roller 267. When the reinforcing fiber piece layer 213 passes, the crushing roller 266 presses the reinforcing fiber piece layer 213 against the rubber sheet 211A, slightly crushing the reinforcing fiber piece layer 213 in the thickness direction as a whole, and on the rubber sheet 211A. The position of the reinforcing fiber piece 212 is further stabilized.

When the rubber sheet 211A and the reinforcing fiber piece layer 213 are conveyed to the supply position D by the conveyor belt 225, the rubber sheet 211B unwound from the winding roll 251 of the supply means 253 is supplied onto the rubber sheet 211A from above and overlapped. Thus, the reinforcing fiber piece layer 213 is interposed between the rubber sheets 211A and 211B. Thereafter, the rubber sheets 211A and 211B and the reinforcing fiber piece layer 213 are supplied to the upper and lower rollers 257 and 258 by the conveyor belt 225. When the rubber sheets 211A and 211B and the reinforcing fiber piece layer 213 pass between the upper and lower rollers 257 and 258, the rubber sheets 211A and 211B are pressed against each other with the reinforcing fiber piece layer 213 interposed therebetween to be bonded. The reinforcing member 210 is manufactured.

At this time, since the upper and lower rollers 257 and 258 are heated to the above-described temperature range, the rubber of the rubber sheets 211A and 211B is plasticized and flows into the gap between the reinforcing fiber pieces 212, and the outer sides of the reinforcing fiber pieces 212 are outside. Rubber adheres to the entire surface. The reinforcing member 210 manufactured in this way is vulcanized and cut into a predetermined length and used for the above-described applications.

Hereinafter, the present invention will be described in more detail with reference to examples.
<Example 1>
In the tire size 155 / 65R13, a reinforcing member that satisfies the conditions shown in the following table in the region from the end of the belt layer to the vicinity of the upper end of the bead core on the outer side of the carcass ply of the sidewall portion in the tire circumferential direction The pneumatic tires for passenger cars of the examples and comparative examples were produced. This reinforcing member was composed of a steel filament plated according to a conventional method and a rubber covering the steel filament, and the thickness was 1.0 mm. In each embodiment, the steel filament does not extend continuously between the widthwise ends of the reinforcing layer, i.e., at least one end of which is terminated in the reinforcing layer and is perpendicular to the reinforcing layer. The projection part which projected the steel filament on at least partially crossed.

In addition, as a reinforcing member in the material stage before pasting, for the fabric density of the reinforcing fiber pieces is different between the tread part side end and the bead part side end, from the tread part side end to the bead part side end, A reinforcing fiber piece having a continuously changing basis weight density was used. One carcass ply (cord material: PET, cord structure: two twists) was used. Further, as the belt layer, a reinforcing cord (material: steel cord (φ0.30 mm), structure: 1 × 3) arranged at an angle of 22 ° with respect to the tire circumferential direction at a driving number of 30/50 mm. Two layers were crossed.

Further, as conventional examples 1-1 and 1-2, tires without reinforcing members were produced. Here, in the conventional example 1-2, the rubber amount of the side portion is reduced as compared with the conventional example 1-1, and the thickness of the side portion is larger in the conventional example 1-1. Examples and comparative examples were equivalent.
Each of the obtained test tires was evaluated according to the following. The results are also shown in the table below.

<Weight index of reinforcing member>
The weight of the used reinforcing member was measured for each test tire. Here, in each example and comparative example, a sheet-like material of about 1100 mm × about 90 mm is used, and the weight of the reinforcing member indicates the weight. For Conventional Examples 1-1 and 1-2, the weight of the rubber attached to the side portion was measured. The results were expressed as an index with the weight of Conventional Example 1-1 as 100. The smaller the value, the lighter and better.

<Tire weight index>
The weight of each test tire was measured and displayed as an index with the weight of Conventional Example 1-1 as 100. The smaller the value, the lighter and better.

<Steering stability>
A vehicle with each test tire mounted on four wheels was subjected to a straight line, lane change, and cornering to comprehensively evaluate steering stability. The results are shown as an index value with the level of the control tire (conventional example 1-1) taken as 100 by calculating the average value of two test drivers. In the calculation, the figures after the decimal point are rounded off. At this time, the difference between the tire of the conventional example 1-1 and the tire of the conventional example 1-2 that does not have a reinforcing member was set to 15. The higher the number, the better the result.

<Cut resistance>
A piece of metal square column of 8cm is placed on the road surface, each test tire is mounted on the front wheel of the test vehicle, the internal pressure is adjusted to 100kPa, and the average load is 300kg at an angle of about 30 degrees. A test was carried out on this square pillar. Starting with a speed of 30 km / h, the test speed is increased by 5 km / h, the speed at which the ply cord breaks in the side portion is the tire cutting speed, and the conventional example 1-1 is displayed as an index of 100. did. The larger this value, the better the cut resistance and the better.

<Bead Durability Test (BF (Bead Fatigure) Drum Test)>
Each test tire was adjusted to an internal pressure of 3.0 kg / cm ² in a room of 25 ± 2 ° C. and then left for 24 hours. Thereafter, the air pressure was readjusted, a load twice as large as the JIS load was applied to the tire, and the tire was run on a drum having a diameter of about 3 m at a speed of 60 km / h for 20,000 km.

* 1) The ratio of the weight density of the tread portion side end portion to the weight density of the bead portion side end portion is shown.

From the results in the above table, although the conventional example 1-2 in which the rubber amount of the side portion was reduced from the normal tire of the conventional example 1-1 and the thickness was thinned, the cut resistance and the steering stability were significantly reduced. On the other hand, it was confirmed that these performances can be complemented by arranging the reinforcing member according to the present invention. Moreover, in the tire of each Example manufactured using the reinforcing member having a density gradient in which the weight density of the tread portion side end portion is higher than the bead portion side end portion, the bead portion side has a higher density than necessary. Thus, the cut-proof performance could be improved without reducing the bead durability.

<Example 2>
Using a device as shown in FIGS. 6 and 7, a steel filament (wire diameter of 0.15 mm) is predetermined between a pair of strip-shaped unvulcanized rubber sheets (each thickness of 0.5 mm) according to the conditions shown in the following table. A reinforcing member in which a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces cut into lengths was interposed was manufactured. In Examples 2-4 and 2-7, a vibration generating device was provided on the conveyor belt, and the rubber sheet on the conveyor belt was vibrated when the reinforcing fiber pieces were dispersed. Moreover, the conditions at the time of pressure bonding of a pair of rubber sheets were set to a pressure of 2 MPa, 80 ° C., and 60 seconds.

<Quantitative evaluation of density non-uniformity>
Each of the obtained reinforcing members was cut into 10 mm squares, and the weight distribution was evaluated. Specifically, 1000 or more samples were obtained at a time, and the weight mi of each sample was weighed. Using this, the average value μ was determined according to the following formula. Further, the standard deviation σ was obtained, and the magnitude of the variation was evaluated based on how many times σ was μ. The results are also shown in the table below. The allowable range of the variation in density depends on the use of the reinforcing member. For example, in the case of reinforcing a tire, if σ / μ is 0.15 or less, the variation is extremely small and excellent. If it is 20 or less, there is no problem, and if it exceeds 0.2, there is a possibility that the variation slightly increases and a problem occurs.

( _Wherein , M _rubber : weight of rubber used to prepare the sample, N: number of cut samples)

As shown in the table above, in Examples 2-1, 2-3, and 2-6, the scattering of the reinforcing fiber pieces slightly occurred, whereas in Examples 2-2 and 2-5, the desired basis weight was obtained. The density was obtained, and the uniformity of the reinforcing fibers was at a level with no problem. Further, in Examples 2-4 and 2-7, the desired density per unit area was obtained, and the uniformity of the reinforcing fibers was very good.

<Example 3>
Using a device as shown in FIGS. 9 and 10, a steel filament (wire diameter of 0.15 mm) is predetermined between a pair of strip-shaped unvulcanized rubber sheets (each thickness of 0.5 mm) according to the conditions shown in the following table. A reinforcing member in which a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces cut into lengths was interposed was manufactured. As the guide body, for each example, for Examples 3-1 to 3-10, the diameter-expanded portion had a linear cross-sectional shape, and for Example 3-11, the diameter-expanded portion A cross-sectional shape having a curved shape was used. About the comparative example 3, the width | variety along the longitudinal direction of a rubber sheet used what is the same from an upper end part to a lower end part. Moreover, the conditions at the time of pressure bonding of a pair of rubber sheets were set to a pressure of 2 MPa, 80 ° C., and 60 seconds.

<Evaluation of non-uniform density>
Each of the obtained reinforcing members was cut out by 1000 mm (1 m) in the longitudinal direction, and equally divided into four in the width direction of the rubber sheet to be sections A to D, and the basis weight density ρA to ρD ( g / m ² ) was calculated. If the weight of each section is mA to mD (g), the area of each section is d1 / 4 (m ² ) (d1: width of reinforcing member (m)), and the weight of rubber used is M _rubber (g). , ΡA = (mA−M _rubber / 4) / (d1 / 4) (g / m ² ). Based on this result, the density nonuniformity a was calculated based on the following formula. Here, there is no uniform preferred range for the density non-uniform amount, and it may be appropriately adjusted according to the intended use. For example, in the reinforcement of the side portion of heavy duty tires such as trucks and buses (the expansion rate of the tread portion side in the sidewall portion is twice), it is only necessary to aim for a non-uniform density a = 2. In the reinforcement of the side portion of the wall portion having an expansion rate of 1.5 times on the tread portion side, the density nonuniformity a = 1.5 may be aimed at. The results are also shown in the table below.
a = (ρB + ρC) / (ρA + ρD)

As shown in the table above, in Comparative Example 3, the density is almost uniform in each section, whereas in each Example, the guide is based on this even when the length of the reinforcing fiber piece is changed. It was confirmed that various reinforcing members having different density nonuniformities can be obtained by appropriately adjusting the size and shape of the body. For example, in Examples 3-2 and 3-7, since the width of the upper portion of the guide body is narrow, the reinforcing fiber pieces are concentrated in the center in the width direction. In Examples 3-5 and 3-10, the reinforcing fiber pieces were slightly scattered outward in the width direction because the height of the position where the width of the expanded diameter portion becomes the effective spreading width was large.

<Example 4>
Using a device as shown in FIGS. 14 and 15, a steel filament (wire diameter of 0.15 mm) is predetermined between a pair of strip-shaped unvulcanized rubber sheets (each thickness of 0.5 mm) according to the conditions shown in the following table. A reinforcing member in which a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces cut into lengths was interposed was manufactured. As the guide body, a shape as shown in FIG. 17A is used for each example, and for the comparative example, the width along the longitudinal direction of the rubber sheet is the same from the upper end to the lower end. A thing was used. Moreover, the conditions at the time of pressure bonding of a pair of rubber sheets were set to a pressure of 2 MPa, 80 ° C., and 60 seconds.

<Calculation method of density μ>
Each of the obtained reinforcing members was cut into 10 mm squares, and the weight distribution was evaluated. Specifically, 1000 or more samples were obtained at a time, and the weight mi of each sample was weighed. Using this, the average value μ was determined according to the following formula. The results are also shown in the table below.

( _Wherein , M _rubber : weight of rubber used to prepare the sample, N: number of cut samples)

<Standard deviation of angle>
As shown in FIG. 19, the angle θi formed with the width direction of the rubber sheet in the orientation direction of the reinforcing fiber pieces 12 in each reinforcing member obtained was measured, and an average value θave was determined according to the following formula.

Further, the standard deviation θσ was determined according to the following formula. If this standard deviation θσ is within 15 °, the orientation is good.

As shown in the above table, in Comparative Example 4, the standard deviation of the angle of the reinforcing fiber piece is considerably large. Since the standard deviation is 60 ° in ideal random spraying, it can be seen that the reinforcing fiber pieces are sprayed randomly in Comparative Example 4. Compared with this, the orientation was significantly improved in each example, and in particular, in Examples 4-1 to 4-4 and Examples 4-6 to 4-9, good orientation was obtained. . Further, in Examples 4-1 and 4-6, the width on the exit side of the guide body is narrower than those in Examples 4-2 and 4-7, respectively, but the effect of the narrowing is saturated, and the orientation is In this respect, it can be seen that it is not much different from Examples 4-2 and 4-7. From this result, even when the length of the reinforcing fiber piece is changed, the width on the exit side of the guide body, the distance from the lower end of the guide body to the rubber sheet surface, and the length of the vertical portion can be set based on this. It was confirmed that good orientation was obtained.

DESCRIPTION OF SYMBOLS 1 Bead core 2 Carcass 3 Belt layer 4 Belt reinforcement layer 5 Reinforcement member 6 Bead filler 7 Bead part 8 Side wall part 9 Tread part 100 Protrusion 101 Reinforcement fiber piece 102 Rubber 10, 110, 210 Reinforcement members 11A, 11B, 111A, 111B, 211A, 211B Strip-shaped unvulcanized rubber sheets 12, 112, 212 Reinforcing fiber pieces 13, 113, 213 Reinforcing fiber piece layers 14, 114, 214 Reinforcing fibers 21, 121, 221 Floor surfaces 22, 122, 222 Fixed frames 23, 123 , 223 Main conveyors 24, 124, 224 Pulleys 25, 125, 225 Conveyor belts 25a, 125a, 225a Conveying sections 28, 128, 228 Upper blades 29, 129, 229 Lower blades 30, 31, 130, 131, 230, 231 Portions 32, 132, 232 Conveying portion 46 146, 246 Guide bodies 46a, 46b Wall portions 47, 147, 247 Mounting plates 50, 150, 250 Support bases 51, 151, 251 Winding rolls 52, 152, 252 Guide rollers 53, 153, 253 Supply means 56, 156, 256 Crimping means 57, 157, 257 Upper rollers 58, 158, 258 Lower rollers 61, 161, 261 Protrusions 62, 162, 262 Entangling rollers 63, 163, 263 Support rollers 66, 166, 266 Crushing rollers 67, 167, 267 Support roller 146A Expanded diameter portion 246A Restricted portion 246B Vertical portion

Claims (25)

1. A pair of left and right bead portions and sidewall portions, and a tread portion continuous between both sidewall portions, and a reinforcing fiber cut into a predetermined length between the pair of strip-shaped unvulcanized rubber sheets in the sidewall portions. A reinforcing member formed by interposing a reinforcing fiber piece layer composed of a plurality of reinforcing fiber pieces is a method of manufacturing a pneumatic tire arranged annularly in the tire circumferential direction,
   In the tire molding process prior to the expansion process at the time of raw tire production, as the reinforcing member, the density density of the reinforcing fiber pieces is higher than the bead part side end part at the tread part side end part. A method for manufacturing a pneumatic tire, comprising: attaching a component having the component to the sidewall portion.
2. 2. The air according to claim 1, wherein the reinforcing member has a density gradient such that the weight density of the reinforcing fiber pieces is 1.5 times or more at the tread portion side end portion with respect to the bead portion side end portion. A method for manufacturing a tire.
3. 2. The method for manufacturing a pneumatic tire according to claim 1, wherein the reinforcing member uses a material having different basis weight densities of the reinforcing fiber pieces on the tread part side and the bead part side from the center in the width direction of the reinforcing member.
4. 2. The method for manufacturing a pneumatic tire according to claim 1, wherein as the reinforcing member, one in which the basis density of the reinforcing fiber pieces continuously changes from the tread portion side end portion to the bead portion side end portion is used.
5. A pneumatic tire manufactured by the method for manufacturing a pneumatic tire according to claim 1.
6. The pneumatic tire according to claim 5, wherein a weight density of the reinforcing fiber pieces is 50 g / m ² or more and 1500 g / m ² or less.
7. The pneumatic tire according to claim 5, wherein the length of the reinforcing fiber piece is 15 mm or more.
8. The pneumatic tire according to claim 5, wherein a diameter of the reinforcing fiber piece is in a range of 0.07 mm to 0.60 mm. *
9. The pneumatic tire according to claim 5, wherein the reinforcing fiber is an inorganic fiber.
10. A method of manufacturing a reinforcing member in which a reinforcing fiber piece layer consisting of a plurality of reinforcing fiber pieces obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of belt-shaped unvulcanized rubber sheets,
    A cutting step of cutting the reinforcing fibers to produce the plurality of reinforcing fiber pieces, and the reinforcement on the one strip-shaped unvulcanized rubber sheet from above one of the strip-shaped unvulcanized rubber sheets extending in the longitudinal direction. A spreading step of spreading the fiber pieces to form the reinforcing fiber piece layer; and supplying the other of the belt-like unvulcanized rubber sheets on the one belt-like unvulcanized rubber sheet and superposing the one and the other A step of interposing the reinforcing fiber piece layer between the belt-shaped unvulcanized rubber sheets, and a pressure-bonding step of pressing the one and the other belt-shaped unvulcanized rubber sheets against each other,
    The manufacturing method of the reinforcing member characterized by performing the said cutting process and the said dispersion | distribution process continuously.
11. In the spreading step, when spreading the reinforcing fiber pieces through the guide body that opens only in the vertical direction, the width along the width direction of the one band-shaped unvulcanized rubber sheet is the upper end portion as the guide body. The method for manufacturing a reinforcing member according to claim 10, wherein the lower end portion is wider and has a portion that gradually increases from above to below.
12. In the spreading step, when spreading the reinforcing fiber pieces through the guide body that opens only in the vertical direction, the width along the longitudinal direction of the one band-like unvulcanized rubber sheet is larger than the upper end portion as the guide body. The method for manufacturing a reinforcing member according to claim 10, wherein the lower end portion has a narrowed portion that is narrow at the lower end portion and gradually decreases from above to below.
13. 13. The method for manufacturing a reinforcing member according to claim 12, wherein the guide body has a vertical portion that does not vary in width along the longitudinal direction of the one band-shaped unvulcanized rubber sheet below the throttle portion.
14. The said guide body uses the thing whose width d in the longitudinal direction of said one strip | belt-shaped unvulcanized rubber sheet of the lower end part of this guide body is 1.0 times or less of the length of the said reinforcing fiber piece. The manufacturing method of the reinforcement member of Claim 12.
15. The method for manufacturing a reinforcing member according to claim 10, wherein, in the spraying step, the one band-like unvulcanized rubber sheet is vibrated.
16. The method for manufacturing a reinforcing member according to claim 15, wherein the one belt-like unvulcanized rubber sheet is vibrated at a vibration frequency of 1 Hz to 1 kHz.
17. A reinforcing member manufacturing apparatus in which a reinforcing fiber piece layer consisting of a plurality of reinforcing fiber pieces obtained by cutting reinforcing fibers into a predetermined length is interposed between a pair of belt-shaped unvulcanized rubber sheets,
    Cutting means for cutting the reinforcing fibers to produce the plurality of reinforcing fiber pieces, and the reinforcing material on the one belt-like unvulcanized rubber sheet from above one of the belt-like unvulcanized rubber sheets extending in the longitudinal direction. Sprinkling means for sprinkling fiber pieces to form the reinforcing fiber piece layer, and supplying and superposing the other of the band-like unvulcanized rubber sheet on the one band-like unvulcanized rubber sheet, the one and the other A supply means for interposing the reinforcing fiber piece layer between the belt-shaped unvulcanized rubber sheets, and a pressure-bonding means for pressing the one and the other belt-shaped unvulcanized rubber sheets against each other,
    The apparatus for manufacturing a reinforcing member, wherein the cutting means and the spraying means are integrally provided.
18. Between the one strip-shaped unvulcanized rubber sheet and the spreading means, there is a pair of wall portions parallel to the longitudinal direction of the one strip-shaped unvulcanized rubber sheet, and an interval between the pair of wall portions is A guide body that is narrower than the width of the one band-shaped unvulcanized rubber sheet is installed, and the distance h from the lower end of the guide body to the surface of the one band-shaped unvulcanized rubber sheet is the reinforcement The apparatus for manufacturing a reinforcing member according to claim 17, wherein the length is 5 times or less the length of the fiber piece.
19. 19. The reinforcing member manufacturing apparatus according to claim 18, wherein the guide body further includes a pair of wall portions parallel to the width direction of the one band-shaped unvulcanized rubber sheet and opens only in the vertical direction.
20. A guide body that opens only in the vertical direction is installed between the spreading means and the one belt-like unvulcanized rubber sheet, and the width of the guide body along the width direction of the belt-like unvulcanized rubber sheet. The apparatus for manufacturing a reinforcing member according to claim 17, which has a portion that is wider at the lower end than the upper end and gradually increases from above to below.
21. A guide body that opens only in the vertical direction is installed between the spreading means and the one belt-shaped unvulcanized rubber sheet, and the width of the guide body along the longitudinal direction of the one belt-shaped unvulcanized rubber sheet The apparatus for manufacturing a reinforcing member according to claim 17, further comprising a throttle portion that is narrower at a lower end portion than at an upper end portion, and has a width that gradually decreases from above to below.
22. The reinforcing member manufacturing apparatus according to claim 21, wherein the guide body has a vertical portion below the throttle portion, the width of which does not vary along the longitudinal direction of the one band-shaped unvulcanized rubber sheet.
23. The apparatus for manufacturing a reinforcing member according to claim 21, wherein a width d of the lower end portion of the guide body in a longitudinal direction of the one band-shaped unvulcanized rubber sheet is 1.0 times or less of a length of the reinforcing fiber piece. .
24. 18. The apparatus for manufacturing a reinforcing member according to claim 17, further comprising a vibration generating mechanism that vibrates the one band-shaped unvulcanized rubber sheet.
25. The reinforcing member manufacturing apparatus according to claim 24, wherein a vibration frequency of the vibration generating mechanism is in a range of 1 Hz to 1 kHz.

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