JP2008290328A - Method and apparatus for producing tire and tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily ejecting the residual air in tires. <P>SOLUTION: In the tire production method using a tire casing 15, a cushion rubber 32 discharged from an extruder 21 is attached onto the tire casing 15, and immediately after attachment, a pair of ridge-formed rollers 41 are pressed on the cushion rubber 32, to form slits at both sides thereof. The slits serve as the exhaust paths for ejecting the residual air in the tire during vulcanization in a post-process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tire manufacturing method, a manufacturing apparatus thereof, and a tire manufactured by the manufacturing method or manufacturing apparatus, and particularly relates to a retread tire.

  Conventionally, when manufacturing a retreaded tire using a vulcanizer, first, the tread rubber of the used tire is removed and polished to expose the retreaded surface, and the damaged portion of the carcass layer is removed from this revitalized surface. To form a recessed hole filling portion. Thereafter, the unvulcanized rubber is pushed out from the extruder while adhering, and the cushion rubber is wound around the rehabilitated surface to cover it, and then the tread rubber is pasted thereon to vulcanize (Patent Document) 1).

In the manufacture of this retreaded tire, the tread rubber to be pasted on the base tire is, for example, an unvulcanized tread rubber with a fin as shown in FIG. In a warm state, the precure tread rubber extruded in step 1 is affixed in an air-tight manner while pressing it in accordance with the contour line of the base tire (contour) using a stitcher such as a stitching roll.
However, when these conventional retreaded tires are manufactured, depending on the contact state of the stitcher, the air that has entered between the precure tread rubber and the base tire cannot be completely discharged, and the air remaining inside Accumulation may occur.

If there is an air trap between the base tire and the precure tread rubber, that part will not adhere well even if vulcanized, and there is a risk of tread separation failure where the fins peel off from the precure tread rubber during running. is there.
However, this internal residual air (air pool) cannot be judged from the appearance, and the presence or absence of residual air must be subjected to a non-destructive inspection such as a cyclo inspection. Yes.

Therefore, in order to remove the residual air, the present applicant has previously drilled a plurality of through holes in the pre-cured tread rubber that has been extrusion-molded from an extruder, wound this around a base tire, and during vulcanization A method for manufacturing a retread tire has already been proposed in which air (residual air) taken in at the time of winding is discharged from the through hole to the outside with a pressure of (see Patent Document 2).
FIG. 6 is a perspective view of a main part of an apparatus for carrying out the conventional method for manufacturing a retread tire.
This rehabilitated tire manufacturing apparatus is configured to move the slit 120 of the venting device 114 in the vertical direction toward the support base 122 with respect to the band-shaped precured tread rubber 110 that is pushed out of an extruder (not shown) and is conveyed on the conveyor 100. The plurality of through-holes 126 are formed at a predetermined pitch over the entire surface of the precure tread rubber 110.

In this retreaded tire manufacturing apparatus, the precure tread rubber 110 in which the through-holes 126 are drilled is conveyed to a support device that rotatably supports the base tire, and its tip is attached to the outer periphery of the base tire (not shown). The pedestal tire is rotated and wound once, and then cut, and the precured tread rubber 110 is pressed by a crown stitcher and a shoulder stitcher to be stuck to the pedestal tire.
Thereafter, the base tire to which the precure tread rubber 110 is adhered is vulcanized with a known mold. At this time, residual air between the tread rubber 110 and the base tire is pressurized during vulcanization. Is discharged to the outside through the through hole 126.

However, in this tire manufacturing method, the venting device 114 having a plurality of drills 120 is driven up and down to form the through holes 126 in the thick precure tread rubber 110, so that a large facility is required. There is a problem that it costs not only.
Japanese Patent Laid-Open No. 9-239864 JP-A-8-025515

  The present invention has been made in order to solve the above-described problems in the manufacture of retread tires, and its purpose is to provide a cushion rubber and a pre-roller wound around a base tire without requiring large facilities as in the prior art. It is to make it possible to easily discharge air from between the cure treads and prevent air from being accumulated in the manufactured retreaded tire.

The invention of claim 1 is a method for manufacturing a tire, the step of attaching a cushion rubber on a base tire, the step of forming a slit to be an air discharge slit in the cushion rubber attached to the base tire, And a step of attaching a precure rubber to the base tire after the slit is formed in the cushion rubber.
According to a second aspect of the present invention, in the tire manufacturing method according to the first aspect, the slit is formed in a cushion rubber adhered to a shoulder portion of a base tire.
According to a third aspect of the present invention, in the tire manufacturing apparatus, a support body that rotatably supports the base tire, a molding apparatus that molds cushion rubber to be attached to the base tire supported by the support body, and a supply from the molding apparatus The cushion rubber affixed to the base tire is provided with means for forming a slit serving as an air discharge slit.
According to a fourth aspect of the present invention, in the tire manufacturing apparatus according to the third aspect, the means for forming the slit includes a protrusion for forming the slit on a peripheral surface thereof and is pressed against the base tire. It is a rotating roller.
According to a fifth aspect of the present invention, in the tire manufacturing apparatus according to the fourth aspect, the roller has a plurality of protrusions arranged in parallel at an arbitrary angle with respect to the rotation axis of the roller. To do.
A sixth aspect of the present invention is a tire, which is manufactured by the tire manufacturing method according to the first or second aspect or the tire manufacturing apparatus according to any one of the third to fifth aspects.

(Function)
According to the present invention, the cushion rubber which is molded with the molding machine of the cushion rubber and is pasted on the base tire by pressing the pair of ridged rollers from both sides to the cushion rubber immediately after being pasted on the base tire. A slit is formed in. This slit becomes a discharge passage for the air entrapped inside when the precure tread rubber is stuck to the base tire. That is, the residual air is easily discharged to the outside through the slit at the pressure during vulcanization.
Moreover, the roller with the ridges can be formed by continuously pressing the rotating base tire in the direction opposite to the base tire by the rotation of the base tire and continuously forming the slit in the cushion rubber.
The distance between the pair of rollers is changed according to the size of the base tire, or the angle (elevation angle) on the vertical plane of the rotation axis of the roller is adjusted.

According to the present invention, an exhaust slit can be automatically formed in the cushion rubber with a simple configuration, and therefore air taken in between the cushion rubber and the precure tread rubber can be eliminated at low cost.
Further, there is no possibility that a gap is formed between the cushion rubber and the precure tread rubber, or that the separation occurs from the gap during traveling.

The present invention will be described with respect to its embodiments.
FIG. 1 is a front view schematically showing a tire manufacturing apparatus, and FIGS. 2 and 3 are side views showing an enlarged part of the manufacturing apparatus.
The extruder in the tire manufacturing apparatus is the same as the conventional one. Here, for example, a tire manufacturing apparatus using the extruder according to the application of the present applicant described in Patent Document 1 is shown as an embodiment.

  In the figure, reference numeral 11 denotes a rail installed on the floor surface 12 extending in the front-rear direction. A slide bearing 14 fixed to the lower end of the tire holding device 13 is slidably engaged with the rail 11. The tire holding device 13 receives a driving force from a driving means (not shown) and is guided by the rail 11 to move in the front-rear direction.

  The tire holding device 13 has a holding rim 16 on which a base tire 15 is mounted, and the holding rim 16 rotates together with the base tire 15 when receiving a driving force from driving means (not shown). The tire holding device 13 can also fill the base tire 15 attached to the holding rim 16 with air of a predetermined pressure.

  Here, the base tire 15 removes and grinds the tread rubber of the used tire with a buffing machine to expose the reclaimed surface 17, and when the carcass layer has a damaged portion, the damaged portion is removed to remove the regenerated surface. A recessed hole filling portion 17 is formed.

An extruder 21 is installed on the floor 12 behind the tire holding device 13 in the drawing, and the extruder 21 has a substantially cylindrical cylinder barrel 22 extending in the left-right direction in the drawing. The cylinder barrel 22 contains a screw that rotates by receiving a driving force from the drive motor 23. When this screw is rotated by the drive motor 23, unvulcanized rubber supplied into the cylinder barrel 22 through the hopper 25. Is conveyed forward in the cylinder barrel 22. A head 27 is fixed to the front end of the cylinder barrel 22, and a passage through which the unvulcanized rubber conveyed by the screw passes is formed in the head 27. At the front end of the head 27, a base 29 disposed close to the rehabilitation surface 17 of the base tire 15 is attached. The base 29 is formed with an extrusion port having a predetermined shape.
The unvulcanized rubber conveyed to the base 29 is extruded while adhering to the retreading surface 17 of the base tire 15 from the extrusion port of the base 29 and wound around the retreading surface 17 to become a cushion rubber 32.
The above configuration is the same as that described in Patent Document 1.

Here, in this embodiment, as shown in FIG. 2, a pair of protruding rollers 41 for forming slits are arranged on both left and right sides of the base tire 15 to which the cushion rubber 32 is attached. .
That is, a support base 44 is provided at the upper end portion of the tire holding device 13, and a roller support member 46 that supports the rotating shaft 42 of the roller 41 with a ridge is attached to the support base 44 so as to be slidable left and right in the figure. It has been. The ridged roller 41 has a plurality of ridges 48 formed on its circumferential surface at equal intervals and in parallel. The protrusion 48 is lightly pressed against the rehabilitation surface 17 of the shoulder portion of the base tire 15, and receives a driving force from the rotating base tire 15 and rotates together.

  As described above, the roller support member 46 is slidably attached to the support base 44 left and right in FIG. 2, and the protrusion 48 of the roller 41 with protrusions can contact the shoulder portion of the table diamond 15. Thus, according to the size of the base tire 15 and its outline (contour), the rotation shaft 42 is configured to be adjustable in angle within a vertical plane. Further, the roller support member 46 includes, for example, a spring urging means (not shown) in order to press the protruding roller 41 of the rotating shaft 42 against the retread surface 17 of the base tire 15 with a predetermined pressure.

  The interval (pitch) of the protrusions 48 of the roller 41 with protrusions, the length and angle of the protrusions 48 can be arbitrarily selected according to the size of the base tire 15 and the like. Moreover, the said protrusion 48 does not necessarily need to be equidistant.

Next, a method for manufacturing a retread tire will be described.
First, the base tire 15 from which the tread rubber is removed is mounted on the holding rim 16 of the tire holding device 13, and then the base rim 15 is rotated by rotating the holding rim 16 by a driving device (not shown).
Next, the unvulcanized rubber that becomes the cushion rubber 32 is extruded from the base 29 of the extruder 21 that is disposed close to the base tire 15 and wound around the rehabilitated surface 17 of the base tire 15.

As shown in FIG. 1, the roller 41 with the ridges attached to the support base 44 is lightly pressed against the shoulder portion at the downstream portion of the base tire 15 rotating as viewed from the extruder 21. It is rotating.
Therefore, the cushion rubber 32 wound around the base tire 15 passes through the protruding roller 41 while being bitten and bitten in a heated and flexible state immediately after discharge. During the passage, as shown in FIG. 2, the protrusions 48 continuously form the slits 34 opened on the shoulder portion of the base tire 15, that is, on the side in the width direction of the cushion rubber 32.

  FIG. 3 shows a roller 41 with a ridge having an angle different from that in FIG. In this embodiment, the ridge 48 of the roller 41 with the ridge shown in FIG. 2 is parallel to the central axis, but has an angle with respect to the central axis. Therefore, the length of the air vent slit 34 formed in the cushion rubber 32 is slightly increased, and the area of the air vent slit 34 is increased accordingly.

  As described above, after the cushion rubber 32 having the slits 34 is attached to the rehabilitated surface 17 of the base tire 15, the precure tread rubber being conveyed is attached to the outside of the cushion rubber 32 as in the prior art. Then, after pasting around the base tire 15 for one turn, it is cut.

Here, FIG. 4 is a cross-sectional view showing an example of the precure tread rubber 51 to be affixed on the cushion rubber 32, and FIG. 5 is a retread tire in which the precure tread rubber 51 shown in FIG. FIG.
As shown in the figure, the precure tread rubber 51 includes a thick flat tread portion 52, a shoulder portion 54 formed of steeply inclined surfaces at both ends of the tread portion 52 in the tire width direction, and a tire width of the shoulder portion 54. It consists of fins or wings 56 composed of gently inclined surfaces at both ends in the direction.

  When the fin 56 of the precure tread rubber 51 is attached to the base tire 15, an appropriate stitcher 58 such as a stitching roller is used. In particular, the portion of the fin 56 is matched to the contour of the shoulder portion of the base tire 15. Bend and paste.

At the time of this pasting, the air entrained between the cushion rubber 32 and the precure tread rubber 51 is pressurized in the next vulcanization step and discharged to the outside from the slit 34.
For this reason, the remaining of an air reservoir between the cushion rubber 32 and the precure tread rubber 51 as in the conventional case is greatly suppressed.

It is a front view which shows a base tire manufacturing apparatus schematically. In order to show the relationship between the base tire covered with the cushion rubber in the base tire manufacturing apparatus shown in FIG. FIG. 3 is a side view of a base tire manufacturing apparatus that is similar to FIG. 2 but includes different ridged rollers. It is sectional drawing which shows an example of the precure tread rubber affixed on cushion rubber. It is sectional drawing of the retreaded tire which affixed the precure tread rubber shown in FIG. 4 on the base tire. It is a perspective view of the principal part of the apparatus which enforces the manufacturing method of the conventional retreaded tire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Rail, 12 ... Floor, 13 ... Tire holding device, 14 ... Slide bearing, 15 ... Stand tire, 16 ... Holding rim, 17 ... Rehabilitation surface, 21. .... Extruder, 22 ... cylinder barrel, 23 ... drive motor, 25 ... hopper, 27 ... head, 29 ... base, 32 ... cushion rubber, 34 ... slit, 41 ... Roller with ridge, 42 ... Rotating shaft, 44 ... Support base, 46 ... Roller support member, 48 ... Projection, 51 ... Precured tread rubber, 52 ... -Tread part, 54 ... shoulder part, 56 ... fin, 58 ... stitcher.

Claims (6)

A process of attaching cushion rubber on the base tire;
Forming a slit to be an air discharge slit in the cushion rubber affixed to the base tire;
After forming the slit in the cushion rubber, a step of attaching a precure rubber to the base tire;
A method for manufacturing a tire, comprising: In the tire manufacturing method according to claim 1,
The said slit is formed in the cushion rubber affixed on the shoulder part of the base tire, The manufacturing method of the tire characterized by the above-mentioned. In tire manufacturing equipment,
A support for rotatably supporting the base tire;
A molding device for molding a cushion rubber to be attached to a base tire supported by the support;
A tire manufacturing apparatus comprising: a cushion rubber supplied from the molding apparatus and attached to the base tire, and means for forming a slit serving as an air discharge slit. In the tire manufacturing apparatus according to claim 3,
The tire forming apparatus according to claim 1, wherein the means for forming the slit is a roller that includes a protrusion for forming the slit on a peripheral surface thereof and is rotated by being pressed by the base tire. In the tire manufacturing apparatus according to claim 4,
The tire manufacturing apparatus according to claim 1, wherein the roller includes a plurality of protrusions arranged in parallel at an arbitrary angle with respect to a rotation axis of the roller.   A tire manufactured by the tire manufacturing method according to claim 1 or 2 or the tire manufacturing apparatus according to any one of claims 3 to 5.

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