JP2009000861A - Manufacturing process of retreaded tire and manufacturing apparatus of retreaded tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent air containment between cushion rubber and a precure tread with a fin in a product when a retreaded tire is manufactured. <P>SOLUTION: When (a) denotes an intersection between an extension line L1 of a cushion rubber sheet crown part outer surface 14A and an extension line L2 of a cushion rubber side part outer surface 14B when seeing an outer border line of a cushion rubber sheet 14 stuck onto a stand tire 12, (b) denotes an intersection between an outer surface 10Aa of a thick walled part 10A and a steep slope 10Ba when the precure tread 10 is arranged in parallel to a rotary shaft of the stand tire 12 and (c) denotes an intersection between the steep slope 10Ba and a gentle slope 10Ca, the precure tread 10 and the stand tire 12 are stuck together by setting dimensional relation between them in advance so that the intersection (a) is arranged between the intersection (b) and the intersection (c). Thereby the precure tread 10 can be certainly stuck by pressing along a shape of the stand tire 12 to prevent occurrence of float between the cushion rubber sheet 14 and the precure tread 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a retread tire manufacturing method and a retread tire manufacturing apparatus, and more particularly to a retread tire manufacturing method and a retread tire manufacturing apparatus suitable for joining a precure tread having fins to a base tire. About.

As a method for manufacturing a retread tire, there is a method using a molding machine that sets a precure tread (PCT), which is a vulcanized belt-like rubber member, on a peripheral surface of a buffed base tire via a raw cushion rubber sheet.
The molding machine has a high-pressure type separate stitcher, and escapes air on the joint surface from the inner side to the outer side in the width direction of the tread while pressing the precure tread.

  As the precure tread, a precure tread that is thick and has a certain thickness in the width direction may be used (for example, see Patent Document 1). By the way, the radius of curvature of the shoulder portion of the buffed base tire is much smaller than the radius of curvature of the tread central portion, so even if the precure tread is pressed and pasted to the base tire using a stitcher etc. Meat precure tread has a strong force to return to the original planar shape (in contrast to the adhesive strength of the pasted portion), so that the outer portion of the precure tread may be peeled off from the shoulder portion.

On the other hand, as a precure tread, there is a precure tread having tapered thin fin portions on both sides of a thick portion, and there is a method of sticking the fin portion to a shoulder portion of a base tire. However, when such a fin portion is attached to the shoulder portion of the base tire, the shape of the shoulder portion of the completed retread tire becomes large uneven, and wrinkles occur on the shoulder portion of the retread tire due to distortion during running There is.
Japanese Patent Application Laid-Open No. 09-070903

  The present invention has been made to solve the above-described problems, and provides a method for manufacturing a retread tire and an apparatus for manufacturing a retread tire that can prevent air entry in a product between a cushion rubber and a finned precure tread. Objective.

  The invention according to claim 1 is a method for manufacturing a retread tire to which a precure tread is pasted from the outer peripheral surface to a part of the side surface of the pedestal tire. A polishing step for polishing the portion, a cushion rubber forming step for forming a cushion rubber layer made of unvulcanized rubber on the portion where the precure tread is applied, and a belt-like precure tread is wound on the cushion rubber sheet. A pre-cured tread attaching step, and a step of vulcanizing the cushion rubber sheet and adhering the pre-cured tread to the base tire, and the pre-cured tread is a thick wall that contacts the road surface And a steep portion that is disposed on the outer side in the tread width direction of the thick part and is inclined so that the thickness gradually decreases toward the outer side in the tread width direction. A steeply inclined portion having a surface, and a gentle slope that is disposed outside the steeply inclined portion in the tread width direction and has a smaller inclination angle than the steeply inclined portion so that the thickness gradually decreases toward the outside of the tread width direction The cushion rubber sheet having a surface and a gently inclined fin portion that is thinner than the steeply inclined portion, and when the base tire on which the cushion rubber sheet is formed is viewed in a cross-section in the width direction An intersection of an extension line of the cushion rubber seat crown portion and an extension line of the cushion rubber seat side portion in the outer contour line of the a is defined as a, and the thick portion and the steep slope when the precure tread is viewed in the cross section in the width direction And the intersection of the steep slope and the gently inclined surface is c, and the intersection a is arranged between the intersection b and the intersection c. After setting the dimensional relationship of the tread and the base tire in advance, pasting the precured tread to the base tire through the cushion rubber sheet, it is characterized in that.

Next, the manufacturing method of the retreaded tire of Claim 1 is demonstrated.
First, in the polishing step, the precured tread pasted portion of the used tire used as a base tire is polished with a buff or the like to remove the old tread as in the prior art.
In the next cushion rubber attaching step, a cushion rubber layer made of unvulcanized rubber is formed on the precure tread attaching portion.

In the next precure tread attaching step, a belt-like precure tread is wound and attached onto the cushion rubber layer. In addition, when pasting the precure tread, the precure tread is pressed from the center side toward the tread end side using a stitcher as usual, so that no air remains between the precure tread and the cushion rubber layer. Make sure the precure tread is firmly attached to the cushion rubber sheet.
In the final bonding step, the tire is heated using a heating device to vulcanize the cushion rubber layer, and the precure tread is bonded to the base tire.

  Here, in the present invention, after setting the dimensional relationship between the precure tread and the base tire so that the intersection point a is disposed between the intersection point b and the intersection point c, the precure tread is interposed via the cushion rubber layer. Since it is affixed to the base tire, the precure tread can be reliably crimped along the shape of the base tire by the stitcher.

  If the intersection point a is located inside the intersection point b, the thick portion of the precure tread is highly rigid, so even if a stitcher is used, the precure tread can be reliably crimped along the shape of the base tire. In some cases, floating may occur between the cushion rubber layer and the precure tread.

  On the other hand, when the intersection point a is located outside the intersection point c, although there is no problem with crimping, the product shape of the fin portion (near the shoulder portion) becomes uneven, and wrinkles occur in the shoulder portion of the retread tire due to distortion during running. Reduce the appearance quality.

  In the invention according to claim 2, a cushion rubber layer is formed by winding an unvulcanized belt-like cushion rubber a plurality of times around the outer peripheral surface of the base tire, and a thick wall that contacts the road surface with respect to the cushion rubber layer. A steeply inclined portion that is disposed on the outer side in the tread width direction of the thick-walled portion and has a steep slope that is inclined so that the thickness gradually decreases toward the outer side in the tread width direction, and on the outer side in the tread width direction of the steeply inclined portion. It is arranged and has a gently inclined surface whose inclination angle is set smaller than that of the steeply inclined portion so that the thickness gradually decreases toward the outer side in the tread width direction, and is formed thinner than the steeply inclined portion. An apparatus for manufacturing a retread tire to which a precure tread having a gently inclined fin portion is attached, wherein the tire is rotatably supported by a base tire support means, and the pre-tread to be attached to the base tire. The base before pasting the precure tread when the intersection of the thick portion and the steep slope when the cross tread is viewed in a cross section in the width direction is b, and the intersection of the steep slope and the gentle slope is c An intersection point a between an extension line of the cushion rubber layer crown portion and an extension line of the cushion rubber layer side portion in the outer contour line of the cushion rubber layer when the tire is viewed in the cross section in the width direction is the intersection point b and the intersection point c. A belt-shaped rubber supply means for supplying the belt-shaped cushion rubber toward the base tire, a precure tread supply means for supplying the precure tread toward the base tire, and the precure tread. And a stitcher that presses the cushion rubber layer against the cushion rubber layer.

Next, the operation of the retread tire manufacturing apparatus according to claim 2 will be described.
First, the base tire to be rehabilitated is rotatably supported by the base tire support means.
Next, while supplying the belt-like cushion rubber toward the base tire by the belt-like rubber supply means, the base tire is rotated, and the belt-like cushion rubber is wound around the base tire at the position where the pre-cured tread is applied to form the cushion rubber layer. Form.

  Next, the precure tread is supplied to the base tire side by the precure tread supply means, the base tire is rotated, the precure tread is wound on the cushion rubber layer, and the precure tread is cushioned by the stitch rubber layer. Press to.

  Here, when the belt-shaped rubber supply means supplies the belt-shaped cushion rubber toward the base tire, the intersection of the thick portion and the steep slope when the precured tread to be attached to the base tire is viewed in the cross-section in the width direction is b, The extension line of the cushion rubber layer crown portion in the outer contour line of the cushion rubber layer when the base tire before the precure tread is pasted in the cross section in the width direction when the intersection of the gently inclined surface is c, and the cushion Since the intersection point a with the extension line of the rubber layer side portion is disposed between the intersection point b and the intersection point c, the precure tread can be securely pressed against the cushion rubber layer by the stitcher.

  In this way, the tire with the precure tread attached thereto is heated using a heating device, and the cushion rubber layer is vulcanized, whereby the precure tread is bonded to the base tire, and a retread tire is completed.

  According to a third aspect of the present invention, a cushion rubber layer is formed by extruding unvulcanized cushion rubber on the outer peripheral surface of a base tire, and a thick portion that contacts the road surface with respect to the cushion rubber layer, and the thick wall A steeply inclined portion having a steep slope that is disposed on the outer side in the tread width direction of the portion and has an inclination so that the thickness gradually decreases toward the outer side in the tread width direction, and is disposed on the outer side in the tread width direction of the steeply inclined portion. A gently inclined fin portion having a gently inclined surface whose inclination angle is set to be smaller than that of the steeply inclined portion so that the thickness gradually decreases toward the outside, and having a thickness thinner than that of the steeply inclined portion. An apparatus for manufacturing a retread tire for attaching a precured tread, comprising: a base tire supporting means for rotatably supporting the base tire; and the precured tread to be attached to the base tire. When the intersection of the thick portion and the steep slope when viewed in a direction cross section is b, and the intersection of the steep slope and the gentle slope is c, the width of the tire before the precure tread is pasted The intersection point a between the extension line of the cushion rubber layer crown portion and the extension line of the cushion rubber layer side portion in the outer contour line of the cushion rubber layer when viewed in the direction cross section is between the intersection point b and the intersection point c. A cushion rubber extruding means for extruding the cushion rubber so as to adhere to the base tire, a precure tread supply means for supplying the precure tread to the base tire side, and the precure tread for the cushion. And a stitcher that presses against the rubber layer.

Next, the operation of the retread tire manufacturing apparatus according to claim 3 will be described.
First, the base tire to be rehabilitated is rotatably supported by the base tire support means.
Next, the cushion rubber is pushed out by the cushion rubber extruding means so as to adhere to the base tire, and the base tire is rotated to form a cushion rubber layer at the position where the precure tread is attached to the base tire.

  Next, the precure tread is supplied to the base tire side by the precure tread supply means, the base tire is rotated, the precure tread is wound on the cushion rubber layer, and the precure tread is cushioned by the stitch rubber layer. Press to.

  Here, when the cushion rubber push-out means pushes the cushion rubber toward the base tire, the intersection of the thick portion and the steep slope when the precured tread to be attached to the base tire is viewed in the cross section in the width direction is b, When the intersection of the inclined surfaces is c, an extension line of the cushion rubber layer crown portion in the outer contour line of the cushion rubber layer when the base tire before the precure tread is pasted in the cross section in the width direction, and the cushion rubber Since the intersection point a with the extension line of the layer side portion is disposed between the intersection point b and the intersection point c, the precure tread can be securely pressed against the cushion rubber layer by the stitcher.

  In this way, the tire with the precure tread attached thereto is heated using a heating device, and the cushion rubber layer is vulcanized, whereby the precure tread is bonded to the base tire, and a retread tire is completed.

  As described above, according to the method for manufacturing a retreaded tire and the apparatus for manufacturing a retreaded tire according to the present invention, there is an excellent effect that it is possible to prevent air from entering the product between the cushion rubber and the precure tread.

[First Embodiment]
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a cross-section in the width direction of the precure tread 10 and a cross section along the rotation axis of the base tire 12 before the precure tread 10 is attached.

The base tire 12 has an old tread removed, and a part of the outer peripheral surface and the side portion where the precure tread 10 is pasted are buffed in advance.
A thin cushion rubber layer 14 is provided on the outer surface of the buffed portion of the base tire 12 (rehabilitation surface 117: precure tread application portion). The cushion rubber layer 14 of the present embodiment is formed by winding a wide unvulcanized rubber sheet (not shown) having a constant width and a constant thickness around the base tire 12 for one turn.

  When the base tire 12 is a truck and bus tire, the dimensions and the like of each part are preferably set as follows. As shown in the cross-sectional view of FIG. 1, the curvature radius R of the crown portion 12A is preferably in the range of 500 to 800 mm. The inclination angle θ of the side portion 12B with respect to the direction orthogonal to the tire rotation axis is preferably in the range of 20 to 35 °. As shown, it is preferable that the intersecting portion of the crown portion 12A and the side portion 12B has an arc shape and the radius of curvature R1 is within a range of 10 to 30 mm.

The precure tread 10 has a thick portion 10A having a constant thickness that comes into contact with the road surface, and the thick portion 10A is inclined so that the thickness gradually decreases toward the outer side in the tread width direction on the outer side in the tread width direction. The steep slope portion 10B having the steep slope 10Ba is provided, and the slope angle is set smaller than the steep slope 10Ba on the outer side in the tread width direction of the steep slope portion 10B so that the thickness gradually decreases toward the outer side in the tread width direction. And a gently inclined fin portion 10C having a thickness that is thinner than the steeply inclined portion 10B.
In the case of truck and bus tires, the thickness of the precure tread 10 is preferably 160 to 300 mm in the thick portion 10A, 10 to 20 mm in the steeply inclined portion 10B, and 10 to 20 mm in the slowly inclined fin portion 10C. The width w (see FIG. 1) of the steeply inclined portion 10B is preferably 5 to 18 mm.

  Here, as shown in FIG. 1, the extension line L1 of the outer surface 14A of the cushion rubber sheet crown when viewing the outer contour line of the cushion rubber layer 14 affixed to the base tire 12, and the outer surface 14B of the cushion rubber side portion The intersection point of the extended line L2 is a, the intersection point between the outer surface (tread surface) 10Aa of the thick portion 10A and the steep slope 10Ba when the precure tread 10 is arranged parallel to the rotation axis of the base tire 12, and the steep slope The dimensional relationship between the precure tread 10 and the base tire 12 is set in advance so that the intersection point a is located between the intersection point b and the intersection point c, where c is the intersection point of 10Ba and the gently inclined surface 10Ca. .

  The precure tread 10 in which the dimensional relationship is set in this manner is wound around the outer surface of the cushion rubber layer 14 formed on the base tire 12, and the tire equator is used using the stitcher 16 as shown in FIG. By pressing the precure tread 10 from the surface CL toward the precure tread end 10 </ b> D, the precure tread 10 is brought into close contact with the cushion rubber layer 14.

  Thereafter, a necessary portion of the tire is heated using a heating device to vulcanize the cushion rubber layer 14, thereby completing a retread tire in which the precure tread 10 is securely vulcanized and bonded to the base tire 12.

  When the intersection point a is located inside the intersection point b, the thick portion 10A of the precure tread 10 has high rigidity, so that even if the stitcher 16 is used, the precure tread 10 is surely aligned along the shape of the base tire 12. In some cases, pressure cannot be applied, and floating may occur between the cushion rubber layer 14 and the precure tread 10.

  On the other hand, when the intersection point a is located outside the intersection point c, although there is no problem with crimping, the product shape (near the shoulder portion) of the gently inclined fin portion 10C is uneven, and the shoulder portion of the retreaded tire is wrinkled by distortion during running. Occurs and deteriorates the appearance quality.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In FIG. 3, reference numeral 111 denotes a rail that is installed on the floor surface 112 and extends in the front-rear direction. A slide bearing 114 fixed to the lower end of the tire holding device 113 is slidably engaged with the rail 111. Yes. The tire holding device 113 can move in the front-rear direction while being guided by the rail 111 by receiving a driving force from a driving means (not shown). The tire holding device 113 has a holding rim 116 on which the base tire 12 is mounted on the upper part. When the holding rim 116 holds the base tire 12, when receiving a driving force from a driving means (not shown), It rotates around the axis of rotation of the base tire 12 together with the base tire 12.

  An extruder 121 called a cold tuber is installed on the floor surface 112 on the arrow R direction side from the tire holding device 113, and the extruder 121 has a substantially cylindrical cylinder barrel 122 extending in the front-rear direction. Further, a precure tread supply device 220 is disposed on the side of the tire holding device 113 in the direction of arrow L.

  As shown in FIGS. 3 and 4, a screw 124 that rotates by receiving a driving force from a driving motor 123 is accommodated in the cylinder barrel 122. When the screw 124 is rotated by the driving motor 123, a hopper is placed in the cylinder barrel 122. The unvulcanized rubber 126 supplied through 125 is conveyed forward in the cylinder barrel 122. A head 127 is fixed to the front end of the cylinder barrel 122, and a passage 128 through which the unvulcanized rubber 126 conveyed by the screw 124 passes is formed in the head 127.

  As shown in FIGS. 4 and 5, a base 129 disposed near the rehabilitation surface 117 of the base tire 12 is attached to the front end of the head 127, and an extrusion port 130 having a predetermined shape is formed in the base 129. ing. Then, when the unvulcanized rubber 126 is conveyed to the base 129, the unvulcanized rubber 126 is extruded from the extrusion port 130 while adhering to the reclaimed surface 117 of the base tire 12, and outside the rehabilitated surface 117. The cushion rubber layer 14 is molded as the cushion rubber layer 14. The cross-sectional shape of the cushion rubber layer 14 at this time is the same as the shape of the gap between the extrusion port 130 and the outer surface of the base tire as shown in FIG.

  Here, since the unvulcanized rubber 126 at the time of extrusion is at a high temperature (usually 70 ° C. to 100 ° C.), the tackiness value (adhesive force) of the unvulcanized rubber 126 is considerably larger than that at normal temperature. The unvulcanized rubber 126 can be brought into close contact with the pressure at the time of extrusion even if an adhesive (rubber paste) is not applied to the rehabilitated surface 117.

  Here, the extrusion port 130 is formed so that the intersection point a of the cushion rubber layer 14 is disposed between the intersection point b and the intersection point c of the precure tread 10.

(Function)
Next, the operation of this apparatus will be described.
First, the base tire 12 is carried into the tire holding device 13 and is mounted and held on the holding rim 116. Next, air of a predetermined pressure is supplied and filled into the base tire 12 from the tire holding device 13, and then the regenerative surface 117 of the base tire 12 contacts the head 127 and the base 129 of the extruder 121 by the driving means. Move backwards until you do.

  Next, the tire 12 is rotated about the rotation axis by the tire holding device 113 and the extruder 121 is operated to rotate the screw 124 by the drive motor 123. Accordingly, the unvulcanized rubber 126 supplied into the cylinder barrel 122 through the hopper 125 is conveyed forward by the rotation of the screw 124 and supplied to the passage 128 of the head 127. Thereafter, the unvulcanized rubber 126 is extruded through the extrusion port 130 of the die 129, and is pasted as a thin cushion rubber layer 14 having a cross-sectional shape identical to the shape of the extrusion port 130 on the outside of the rehabilitation surface 117. At this time, the unvulcanized rubber 126 is pressed against the reclaimed surface 117 of the base tire 12 by the extrusion pressure, and the inner surface side is adhered.

  Here, at the time of extrusion from the extruder 121 (at the time of sticking to the reclaimed surface 117), the unvulcanized rubber 126 has a high tackiness value (adhesive force) at a high temperature and is considerably higher than that at room temperature. Even if the adhesive (rubber paste) is not applied to the rehabilitated surface 17, the rubber 126 can be brought into close contact with the pressure during extrusion, and the situation where air enters between them can be effectively prevented.

Note that the unvulcanized rubber 126 extruded from the extrusion port 130 and in close contact with the base tire 12, that is, the cushion rubber layer 14 formed on the base tire 12, is shown in FIG. 6 as in the first embodiment. Thus, the intersection point a is disposed between the intersection point b and the intersection point c of the precure tread 10.
As described above, when the unvulcanized rubber 126 is adhered to the entire surface of the rehabilitated surface 117 of the base tire 12 and the cushion rubber layer 14 is completed, the base tire 12 stops rotating and the unvulcanized rubber by the extruder 121 is stopped. The extrusion of 126 is stopped.

Next, while rotating the base tire 12 around the rotation axis, the precure tread 10 is sent out by the precure tread supply device 220, and the precure tread 10 is placed outside the cushion rubber layer 14 in the same manner as in the first embodiment. Wrap and paste.
Next, after removing the tire formed in this way from the tire holding device, it is carried into a vulcanization mold of a known tire vulcanizing device and vulcanized to obtain a retreaded tire.

  Also in the present embodiment, as described above, the intersection point a of the cushion rubber layer 14 is disposed between the intersection point b and the intersection point c of the precure tread 10, and the precure tread 10 is attached. Similar to the configuration, a retread tire in which the precure tread 10 is securely vulcanized and bonded to the base tire 12 is completed.

[Third Embodiment]
As shown in FIG. 7, in the present embodiment, the tire holding device 113 is fixed to the floor surface 112, the belt-shaped rubber supply device 213 is arranged in the direction of arrow R of the tire holding device 113, and the arrow of the tire holding device 113 is used. A precure tread supply device 220 is arranged in the L direction.

  On the floor surface 112, a rail 211 is disposed below the belt-like rubber supply device 213. A slide bearing 214 fixed to the lower end of the belt-like rubber supply device 213 is slidably engaged with the rail 211. ing. The belt-like rubber supply device 213 can move in the rail longitudinal direction (the front and back direction in FIG. 7) while being guided by the rail 211 by receiving a driving force from a driving means (not shown).

  The belt-shaped rubber supply device 213 is rotatably mounted with a reel 217A in which a cushion rubber 215 having a narrow band shape is wound together with the separator 216, and a take-up reel 217B that winds up the separator 216.

  In addition, an arm 218 that extends toward the tire holding device 113 is attached to the belt-shaped rubber supply device 213, and a pair of guide rollers 219 is attached to the tip of the arm 218.

(Function)
Next, the operation of this apparatus will be described.
First, the base tire 12 is carried into the tire holding device 13 and is mounted and held on the holding rim 116. Next, the end of the belt-like cushion rubber 215 pulled out from the reel 217A is attached to the outer peripheral surface (the radially outer side of one side portion) of the base tire 12 via the guide roller 219.

  By moving the belt-shaped rubber supply device 213 while rotating the base tire 12, the belt-shaped cushion rubber 215 is spirally wound around the base tire 12, and the cushion rubber layer 14 can be formed.

  In this device, the control device controls the amount of rotation of the base tire 12 and the amount of movement of the belt-like rubber supply device 213, so that, for example, as shown in FIG. One or more layers of 215 can be laminated to form a cushion rubber layer 14 having partially different thicknesses.

  In the present embodiment, similarly to the second embodiment, the amount of rotation of the base tire 12 and the belt-shaped rubber supply device so that the intersection point a is disposed between the intersection point b and the intersection point c of the precure tread 10. The cushion rubber layer 14 is formed by adjusting the movement amount of 213.

Next, the precure tread 10 is affixed to the outside of the cushion rubber layer 14 in the same manner as in the above-described embodiment while rotating the base tire 12 around the rotation axis.
Next, after removing the tire formed in this way from the tire holding device, it is carried into a vulcanization mold of a known tire vulcanizing device and vulcanized to obtain a retreaded tire.

  Also in this embodiment, since the intersection point a of the cushion rubber layer 14 is disposed between the intersection point b and the intersection point c of the precure tread 10 and the precure tread 10 is attached as described above, the precure tread 10 Thus, a retread tire that is securely vulcanized and bonded to the base tire 12 is completed.

(Test example)
In order to confirm the effect of the present invention, a retread tire was manufactured by the method of the comparative example and the method of the example to which the present invention was applied.
Conventional Example 1: The position of the intersection point a is set to 96 mm from the tire equator plane, the intersection point b is set to 99 mm from the tire equator plane, and the intersection point c is set to 108 mm from the tire equator plane.
Conventional Example 2: The position of the intersection point a is set to 112 mm from the tire equator plane, the intersection point b is set to 99 mm from the tire equator plane, and the intersection point c is set to 108 mm from the tire equator plane.

Example: The position of the intersection point a is set to 105 mm from the tire equator plane, the intersection point b is set to 99 mm from the tire equator plane, and the intersection point c is set to 108 mm from the tire equator plane.
Note that the width of the precure tread is 210 mm, the retread tire is for trucks and buses, the product size is 245 / 70R19.5, the radius of curvature R of the crown portion of the base tire is 500 mm, and the radius of curvature R1 of the shoulder portion of the base tire Was 25 mm, and the inclination angle θ of the base tire side portion was 30 °.

試験の結果、本発明の方法により製造された更生タイヤは、エアー入りが無く、外観品質も良好であった。

As a result of the test, the retreaded tire manufactured by the method of the present invention did not contain air and had good appearance quality.

It is sectional drawing of the base tire which provided the precure tread and the cushion rubber layer. It is sectional drawing of the base tire which affixed the precure tread. It is a side view which shows schematic structure of the apparatus which forms a cushion rubber layer. It is sectional drawing of a head vicinity. It is a front view of the nozzle | cap | die made to contact a base tire. It is sectional drawing of a base tire which has a cushion rubber layer formed with the precure tread and the apparatus of FIG. It is a side view which shows the outline of the apparatus which forms a cushion rubber layer. It is sectional drawing of a base tire which has a cushion rubber layer formed with the precure tread and the apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Precure tread 12 stand tire 10C Slowly inclined fin part 10Ca Slowly inclined surface 10B Steeply inclined part 10Ba Steeply inclined surface 10A Thick part 12 Tires 12A Crown part 12B Side part 13 Tire holding device (base tire support means)
DESCRIPTION OF SYMBOLS 14 Cushion rubber layer 14A Cushion rubber sheet | seat crown part outer surface 14B Cushion rubber side part outer surface 16 Stitcher 17 Rehabilitation surface 113 Tire holding device 117 Rehabilitation surface 121 Extruder (cushion rubber extrusion means)
122 Cylinder barrel 126 Unvulcanized rubber 213 Band rubber supply device (band rubber supply means)
220 Precure tread supply device (Precure tread supply means)
a Intersection a
b Intersection b
c Intersection c
L1 Cushion rubber seat crown extension line L2 Cushion rubber seat side extension line

Claims (3)

A method for manufacturing a retread tire in which a precure tread is pasted over a part of a side surface from an outer peripheral surface of a base tire,
A polishing step for polishing a precured tread pasted portion of a used tire as a base tire;
Cushion rubber forming step of forming a cushion rubber layer made of unvulcanized rubber on the precure tread application part,
A precure tread application step of winding and attaching a belt-shaped precure tread on the cushion rubber sheet,
Vulcanizing the cushion rubber sheet and bonding the precure tread to the tire,
Have
The pre-cured tread has a thick portion that contacts the road surface, and a steep slope portion that is disposed on the outer side in the tread width direction of the thick portion and has a steep slope that is inclined so that the thickness gradually decreases toward the outer side in the tread width direction. And a gently inclined surface that is disposed on the outer side in the tread width direction of the steeply inclined portion and has a gently inclined surface that is set to have an inclination angle smaller than that of the steeply inclined portion so that the thickness gradually decreases toward the outer side in the tread width direction. And a gently inclined fin portion formed thinner than the steeply inclined portion,
The intersection of the extension line of the cushion rubber sheet crown portion and the extension line of the cushion rubber sheet side part in the outer contour line of the cushion rubber sheet when the base tire in which the cushion rubber sheet is formed is viewed in the cross section in the width direction And a
When the intersection of the thick portion and the steep slope when the precure tread is viewed in a cross section in the width direction is b, and the intersection of the steep slope and the gently inclined surface is c,
After preliminarily setting the dimensional relationship between the precure tread and the base tire so that the intersection point a is disposed between the intersection point b and the intersection point c, the precure tread is interposed via the cushion rubber sheet. A method for producing a retread tire, wherein the tire is affixed to the base tire. A cushion rubber layer is formed by winding uncured belt-like cushion rubber a plurality of times on the outer peripheral surface of the base tire, and a thick portion that contacts the road surface with respect to the cushion rubber layer, and a tread of the thick portion A steeply inclined portion having a steep slope that is disposed on the outer side in the width direction and has an inclination so that the thickness gradually decreases toward the outer side in the tread width direction; And a gently inclined fin portion having a gently inclined surface whose inclination angle is set to be smaller than that of the steeply inclined portion so that the thickness gradually decreases, and a thinly inclined fin portion that is thinner than the steeply inclined portion. An apparatus for manufacturing retreaded tires to which cure red is applied,
A base tire support means for rotatably supporting the base tire;
When the intersection of the thick portion and the steep slope when the precure tread to be attached to the base tire is viewed in a cross section in the width direction is b, and the intersection of the steep slope and the gentle slope is c, Intersection point a between the extension line of the cushion rubber layer crown part and the extension line of the cushion rubber layer side part in the outer contour line of the cushion rubber layer when the base tire before pasting the cure tread is viewed in the cross section in the width direction A belt-shaped rubber supply means for supplying the belt-shaped cushion rubber toward the base tire so as to be disposed between the intersection b and the intersection c;
Precure tread supply means for supplying the precure tread toward the base tire;
A stitcher that presses the precure tread against the cushion rubber layer;
A retreaded tire manufacturing apparatus comprising: A cushion rubber layer is formed by extruding unvulcanized cushion rubber on the outer peripheral surface of the base tire, and is disposed on the outer side in the tread width direction of the thick wall portion with respect to the road surface and the thick wall portion with respect to the cushion rubber layer. A steeply inclined portion having a steep slope that is inclined so that the thickness gradually decreases toward the outer side in the tread width direction, and the steeply inclined portion is disposed on the outer side in the tread width direction, and the thickness gradually decreases toward the outer side in the tread width direction. A retread for attaching a precure tread having a gently inclined surface having a gently inclined surface whose inclination angle is set smaller than that of the steeply inclined part and a gently inclined fin part formed thinner than the steeply inclined part. A tire manufacturing apparatus,
A base tire support means for rotatably supporting the base tire;
When the intersection of the thick portion and the steep slope when the precure tread to be attached to the base tire is viewed in a cross section in the width direction is b, and the intersection of the steep slope and the gentle slope is c, Intersection point a between the extension line of the cushion rubber layer crown part and the extension line of the cushion rubber layer side part in the outer contour line of the cushion rubber layer when the base tire before pasting the cure tread is viewed in the cross section in the width direction A cushion rubber push-out means for extruding the cushion rubber so as to adhere to the base tire so as to be disposed between the intersection b and the intersection c;
Precure tread supply means for supplying the precure tread to the base tire side;
A stitcher that presses the precure tread against the cushion rubber layer;
An apparatus for manufacturing a retread tire, comprising:

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