JPH1044213A - Cap structure of tube extruder for tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and inexpensively subject a tube main body for forming a non-puncture tube and an outer layer band to extrusion molding. SOLUTION: A circular hole 48 is formed to the cap 48 provided to the leading end of the die of an extruder and a piece 44 is inserted in and arranged to the circular hole 48 to form an extrusion port for extruding an almost cylindrical tube main body to mold the same. A circular arc-shaped slit hole 54 is formed to the cap along the peripheral edge of the circular hole and a strip like outer layer band having predetermined width is subjected to extrusion molding from the slit hole 54 along the outer periphery of the tube main body. By this constitution, the tube main body for producing a non-puncture tube and the outer layer band are subjected to extrusion molding at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die structure of a tube extruder for a tire used for manufacturing a non-punctured tire in which a puncture preventing liquid is sealed on a tread side formed in two layers.

[0002]

2. Description of the Related Art Tubes used for vehicle tires are:
A nail or the like is easily pierced into the tread side, and if the nail or the like is pierced, a puncture occurs in which the inside air escapes, which hinders the running of the vehicle.

[0003] In order to prevent the air from leaking out of such a tube, there is a non-punctured tube in which the tread portion of the tube has a two-layer structure and a puncture preventing liquid is sealed therein. As shown in FIG. 4, the non-puncture tube 74 provided inside the tire 72 attached to the rim 70 has a double structure of an inner layer 76 and an outer layer 78 on the tread side opposite to the rim 70, Puncture prevention is sealed between the inner layer 76 and the outer layer 78. In the non-punctured tube 74, when a hole is opened by a nail step on the tread side, a puncture preventing liquid closes the hole to prevent air from leaking from the tube. This allows the vehicle to continue running.

[0004] Incidentally, since a tire tube generally manufactured has a single-layer structure, an extruder used for extruding the tire tube has a structure in which a cylindrical tube is extruded by itself. For this reason, it is difficult to extrude and form a non-puncture tube partially having a two-layer structure using an existing tube extruder. For this reason, in order to extrude a non-puncture tube,
Separately, it is necessary to install an extrusion equipment for a non-puncture tube, and the production cost is extremely high.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and proposes a die structure for a tube extruder for a tire which makes it possible to manufacture a non-puncture tube easily and at low cost. The purpose is to do.

[0006]

The invention according to claim 1 is
A die structure of a tube extruder for a tire that extrudes a rubber material supplied into the die from a die provided at a tip of the die of the extruder to form a tube for a substantially cylindrical tire, and is formed by a circular hole. In addition to the first extrusion port from which a substantially cylindrical tube body is extruded, the tube body is formed in a substantially arc shape along the periphery of the circular hole, covers the tread side of the tube body, and is formed between the tube body and the tube body. A slit-shaped second extrusion port is provided, which is formed by extrusion-molding an outer layer band for allowing a puncture prevention liquid to be filled therein.

According to the present invention, the first and second extrusion ports are formed in the die provided at the tip of the die of the extruder. Thereby, the cylindrical tube main body and the outer layer band covering the tread side of the tube main body can be simultaneously extruded and formed.

Thus, there is no need to separately provide an extruder for extruding the outer layer band as the outer layer for forming a space for sealing the puncture preventing liquid in the tube body as the inner layer. The body and the outer zone can be extruded simultaneously. In addition, since the tube body and the outer layer zone can be extruded using an extruder that extrudes only the cylindrical tube body, it is possible to extrude a non-punctured tube easily and at low cost. Become.

Further, since the outer layer band is extruded adjacent to the tube main body, the joining of the tube main body and the outer layer band can be performed after the extrusion step. Thus, it becomes easy to manufacture a non-puncture tube having a space in which a puncture prevention liquid can be sealed. Further, it is possible to cope with the extrusion molding of a tube body other than the non-puncture tube simply by replacing the die with a conventional die having only the first extrusion port.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a tube extruder 10 (hereinafter, referred to as “extruder 10”) to which the present invention is applied. This tube extruder 1
0 is applicable to a general manufacturing process of a tube for a tire.

In the tube extruder 10, rubber (kneaded dough) compounded and kneaded in a refining system is supplied with rubber dough that has been kneaded and heated using a hot-rolling roll in a heating step. This softens the rubber material and improves the dispersion of compounding chemicals. The rubber is passed through a strainer prior to extrusion to remove foreign substances.

As shown in FIG. 3, the extruder 10 extrudes a cylindrical tube main body 52 from a rubber material. When cooled, the tube main body 52 extruded by the extruder 10 is cut into a predetermined length, joined in a ring shape, and then vulcanized to finish as a tire tube.

At this time, the extruder 10 simultaneously extrudes a belt-shaped outer layer band 56 having a predetermined width. By bonding the outer layer band 56 to a predetermined position on the peripheral surface of the tube main body 52, a space in which the puncture preventing liquid can be sealed can be formed between the tube main body 52 and the outer layer band 56. By bonding the outer layer band 56 to the tube main body 52, a non-punctured tube is formed.

As shown in FIG. 1, the extruder 10 comprises:
It comprises an extruding part 12 and a die head part 14. The pushing section 12 is provided with a cylinder 16 having a cylindrical hollow inside, and a screw 18 is arranged inside the cylinder 16. Inside the cylinder 16 of the extruding portion 12, the rubber material from which the above-mentioned heat-filling and removal of foreign substances have been completed is cut into predetermined amounts, and is conveyed and supplied by a belt conveyor or the like. In the extruding unit 12, the screw 18 is rotated by the driving force of a driving unit (not shown), and the rubber material supplied into the cylinder 16 is sent out to the die head unit 14 (the sending direction is shown in FIG. 1). Indicated by arrow A).

At the tip of the cylinder 16, a bolt 20
The die head 22 of the die head section 14 is attached. The axis of the die head 22 is hollow and continuous with the inside of the cylinder 16.
The passage of the rubber material sent out by the screw 18 is formed.

The die head 22 is provided with a spider 24 in a hollow portion. Inside the spider 24, a pipe 26 for supplying talc for preventing sticking of the rubber material extruded from the extruder 10 and a pipe 28 for sucking air containing talc are arranged.

A spindle 30 is mounted on the spider 24. The spindle 30 is mounted on the die head 2
2, the pipes 26 and 28 are bent and inserted through the inside of the rubber material in the direction in which the rubber material is delivered.

A die 32 is attached to the die head 22 on the side opposite to the cylinder 16. This die 3
A part 2 is inserted into the hollow part of the die head 22 and tightly fastened to the die head 22 via a ring-shaped holder 34 and attached.

The inside of the die 32 is hollow, and a passage 36 for a rubber material fed through the die head 22 is formed. The diameter of the passage 36 is reduced and reduced at the intermediate portion, and the diameter of the passage 36 is gradually increased from the narrowed intermediate portion in the direction in which the rubber material is delivered.

A die 38 is provided at the tip of the die 32. The base 38 is arranged so as to close the opening at the tip of the die 32. The base 38 has an end cap 40 attached so as to cover the tip of the die 32.
And a tip of the die 32. A plurality of adjustment screws 42 are screwed into the end cap 40. The tip of the adjusting screw 42 is in contact with the peripheral end surface of the base 38. By rotating and adjusting the adjusting screw 42 and pulling it out from the end cap 40, the position of the base 38 is adjusted in the radial direction of the opening of the die 32. Is moved along. Thereby, the base 38 for the die 32
The mounting position of can be adjusted.

On the other hand, a substantially triangular pyramid-shaped piece 44 is attached to the tip of the spindle 30. This piece 44
The spindle 30 is fixed at a predetermined position on the spindle 30 by a nut 46 screwed to the tip of the spindle 30. Die 3
The passage 36 at the leading end of the widened rubber fabric 2 on the delivery direction side is narrowed by a piece 44, and the piece 40
The rubber material passes between the peripheral edge of the die and the inner surface of the die 32 (passage 36).

By the way, as shown in FIG.
The base 38 has a circular hole 48 into which the piece 44 is inserted. As shown in FIG.
The diameter is gradually reduced on the downstream side in the rubber material sending direction. In the die head portion 14, the periphery of the circular hole 48 formed in the base 38 and the piece 4 inserted and arranged in the circular hole 48 are formed.
The gap formed between the peripheral edge of the rubber material 4 and the peripheral edge of the rubber material 4 forms an extrusion port 50 for extruding the rubber material as a cylindrical tube.

As shown in FIG. 1, the rubber material is guided to the extrusion port 50 by passing between the inner surface of the die 32 and the peripheral surface of the block 44. As a result, as shown in FIG. 3, the rubber material supplied into the die 32 is extruded from the extrusion port 50 through the passage 36 to be formed as a substantially cylindrical tube main body 52.

As shown in FIGS. 1, 2 (A) and 2 (B), a slit 38 is formed in the base 38 along the periphery of the circular hole 48. As shown in FIG. 1, the rubber material passing through the passage 36
You will also be guided to That is, FIG.
As shown in FIG. 2A, a slit 54 is formed in the base 38 at a predetermined position between the circular hole 48 and a position corresponding to the end cap 40.

As shown in FIGS. 2A and 2B, the slit hole 54 is formed in an arc shape along the periphery of the circular hole 48. As shown in FIG. 3, an outer layer band 56 facing a part of the outer peripheral surface of the tube main body 52 is extruded from the slit hole 54 and is formed. FIG. 2 (A)
As shown in the figure, the opening width of both ends of the slit hole 54 is slightly wider than that of the center portion, and the rubber material is extruded from the slit hole 54, so that the width direction (perpendicular to the sending direction) is achieved. Direction), and is extruded into a strip having a substantially uniform thickness.

By joining both ends of the outer layer band 56 in the width direction to the tube body 52, a tire tube having a space between the tube body 52 and the outer layer band 56 in which a puncture preventing liquid can be sealed is manufactured. Can be.

The opening length of the slit hole 54 formed in the base 38, that is, the width dimension of the outer layer band 56 extruded from the slit hole 54, is determined when the outer layer band 56 is formed by the tube body 52. It suffices if a predetermined area on the tread side of the tire tube can be surely covered. Therefore, any material that covers the slit may be used. For example, when the outer layer band 56 is provided so as to cover the region on the tread side half of the tire tube, the slit hole 54 may be formed so that the half circumferential dimension of the tube main body 52 and the opening length of the slit port 56 are substantially the same.

As shown in FIG. 1, a nozzle 58 for suctioning talc and a suction nozzle 60 are attached to the tip of the spindle 30 projecting from the nut 46. The talc blowing nozzle 58 is communicated with the above-mentioned pipe 26, and blows out talc supplied through the pipe 26 from the plurality of blowing holes 58A.

From the extrusion port 50, the rubber material is extruded so as to surround the blowing nozzle 58. Here, by blowing air containing talc from the talc blowing nozzle 58, the tube main body 52 is expanded into a predetermined cylindrical shape, and the inner surface of the tube main body 52 is prevented from being unnecessarily adhered by the talc. I am trying to do it.

The suction nozzle 60 is connected to the pipe 28 described above. The suction nozzle 60 sucks the air blown from the talc blowing nozzle 58 into the tube main body 52, and causes the tube main body 52 to be narrowed. Thus, the extruded tube main body 52 is formed in a flat band shape, so that the operation in the next step is facilitated. At this time, the excess talc inside the tube body 52 is also sucked out from the tube body 52 at the same time.

Next, the operation of the present embodiment will be described. Rubber (kneaded dough) compounded and kneaded in a scouring system to form a tube for tires is subjected to kneading heat removal and removal of foreign substances by a strainer, cut into small pieces, and then conveyed by a belt conveyor or the like to be transferred to a rubber conveyor. The dough is supplied to the cylinder 16 of the extruder 10.

In the extruder 10, the rubber material supplied to the cylinder 16 is continuously sent to the die head 14 by the rotation of the screw 18. In the die head section 14,
The rubber material delivered from the cylinder 16 by the screw 18 is pushed toward the passage 36. As a result, the rubber material is continuously extruded from the extrusion opening 50 formed by the base 38 and the piece 44 arranged at the tip end of the passage 36 and the slit hole 54 formed in the base 38, Outer layer band 56 together with the tubular body 52
Are molded simultaneously.

As described above, in the extruder 10, the base 38
The tube main body 52 can be formed by the piece 44 inserted between the circular hole 48 formed in the base 38 and the circular hole 48 of the base 38, and by forming the slit hole 54 in the base 38, At the same time, the tube body 52
The outer layer band 54 for enclosing the puncture preventing liquid can be formed between the outer layer band 54 and the outer layer band 54. That is, a circular hole 48 for extruding the tube main body 52 is provided in an extruder conventionally used for extruding only the cylindrical tube main body 52.
In addition to this, the outer layer 56 for manufacturing the non-punctured tube can be simultaneously extruded together with the tube main body 52 by attaching the base 38 having the slit hole 54 formed therein.

As a result, it is possible to manufacture a non-puncture tube simply by changing a base (and a piece if necessary) of an existing extruder without installing a dedicated facility, thereby simplifying a manufacturing process of a non-puncture tire. In addition, the manufacturing cost of the non-puncture tire can be significantly reduced.

The tube body 52 and the outer layer band 56 extruded by the extruder 10 are superposed and cooled. At this time, the operation of bonding the outer layer band 56 to the tube main body 52 becomes easy by making the cylindrical tube main body 52 flat and flattened.

When the tube main body 52 to which the outer layer band 56 is adhered is cut into a predetermined length and joined in a ring shape, it is vulcanized and finished as a non-punctured tube. Thereby, for example, as shown in FIG. 4, the outer layer band 56 is used as the outer layer 78, and the tube main body 52 facing the outer layer band 56 is used as the inner layer 76, and between the inner layer 76 and the outer layer 78 (the tube main body 52 and the outer layer band 56). The non-puncture tube 74 in which the puncture prevention liquid is sealed can be formed in the period (between), and thereby, it is possible to prevent air leakage (puncture) from the tire 72 attached to the rim 70.

As described above, the tube main body 52 and the outer layer band 5
By extruding 6 at the same time, production of a non-punctured tube becomes extremely easy.

The present embodiment described above is an example of the present invention, and does not limit the configuration of the present invention. The present invention provides, in order to form a non-punctured tube, a conventional die by extruding the tube body by itself, by providing a die with a slit-shaped extrusion port for extruding the tube layer and the outer layer band in the die. The extruder is used to extrude the outer layer zone simultaneously with the tube main body, thereby making it possible to produce a non-punctured tube at low cost.

[0039]

As described above, according to the present invention, the tube body and the outer layer band can be simultaneously extruded and formed by a single die, so that the tread surface can be punctured using a conventional tube extruder. An excellent effect is obtained in which a tube for a tire formed in a two-layer structure of an inner layer and an outer layer capable of enclosing the prevention liquid can be easily manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an extruder applied to the present embodiment.

2A is a schematic plan view showing a die to which the present invention is applied, and FIG. 2B is a schematic sectional view of the die taken along line 2B-2B in FIG. 2A.

FIG. 3 is a schematic perspective view showing a tube main body and an outer layer band which are simultaneously extruded by an extruder.

FIG. 4 is a schematic sectional view of a tire showing a non-puncture tube provided inside the tire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extruder 12 Extrusion part 14 Die head part 32 Die 38 Cap 44 Piece 48 Round hole 50 Extrusion port (1st extrusion port) 52 Tube main body 54 Slit hole (2nd extrusion port) 56 Outer layer zone

Claims (1)

[Claims] 1. A die structure of a tube extruder for a tire, which extrudes a rubber material supplied into the die from a die provided at a tip of the die of the extruder to form a substantially cylindrical tire tube. In addition to the first extrusion port formed by extruding a substantially cylindrical tube body formed by a circular hole, the tube is formed in a substantially arc shape along the periphery of the circular hole and covers the tread side of the tube body. A base structure for a tube extruder for a tire, wherein a slit-shaped second extrusion port is provided between the main body and the main body, the second layer being extruded with an outer layer for extruding an anti-puncture liquid.