JP5497371B2 - Pneumatic tire molding method and band molding machine used therefor - Google Patents

Description

  The present invention provides an inner liner rubber sheet having joint surfaces that are inclined with respect to the thickness direction and are parallel to each other at the front and rear ends in a longitudinal section. A tire manufacturing method in which an annular inner liner rubber is formed by wrapping around a band drum so that a joining surface at an end faces radially inward and a part of a joining surface at a rear end overlaps radially outside a joining surface at a front end More particularly, the present invention relates to a tire molding machine used therefor, and particularly to a machine that can reliably suppress the occurrence of cracks in the joint surface between the front end and the rear end of an inner liner in a product tire.

  The tire is obtained by assembling a plurality of members constituting the tire and molding an unvulcanized tire and then vulcanizing the tire. As one manufacturing method for molding an unvulcanized tire, an annular inner liner rubber which is an inner liner constituting the inner surface of the tire and a carcass ply located on the outer peripheral side thereof, a band together with these members or other members. A carcass band or a cylindrical body is formed by being wound around a molding drum called a drum, and the remaining members are assembled after the carcass band or the cylindrical body is transferred to another molding drum.

  In the conventional tire manufacturing method, the annular inner liner rubber is formed by winding an inner liner rubber sheet 90 shown in a longitudinal section in FIG. 1 around a band drum. The inner liner rubber sheet 90 has joint surfaces 91a and 92a parallel to each other that are inclined with respect to the thickness direction in the longitudinal section at the front end 91 and the rear end 92, respectively.

  FIG. 2 is a cross-sectional view showing portions of the annular inner liner rubber corresponding to the front and rear ends of the inner liner rubber sheet 90. The annular inner liner rubber 99 is formed by winding the inner liner rubber sheet 90 around the band drum 98. In this case, the joint surface 91a of the tip 91 faces radially outward, the joint surface 92a of the rear end 92 faces radially inward, and the joint surface of the rear end 92 radially outward of the joint surface 91a of the tip 91 is formed. It winds so that a part of 92a may overlap.

  Thereafter, in order to ensure the adhesion between the joining surface 91a of the leading end 91 and the joining surface 92a of the trailing end 92, the outside crimping machine 81 called a jam machine has the trailing end 92 directed inward from the outside in the radial direction. Pressing is done.

  However, as shown in FIG. 3 in the state of the annular inner liner rubber after the rear end 92 is pressed by the outer crimping machine 81, the front end 91 and the rear end 92 of the inner liner rubber sheet 90 are removed by the outer crimping machine 81. Even if the joining portion is crimped from the outside, there is a possibility that a portion 93 of the leading end joining surface 91a that does not overlap with the rear end joining surface 92a remains, and if this non-overlapping portion 93 remains, the tire after vulcanization Cracks called "inner liner cracks" that open on the inner surface occur, and this tire is checked by appearance inspection before shipping and cannot be shipped, resulting in a decrease in yield. It was sought after.

  The present invention has been made in view of such problems, and provides a tire manufacturing method and a tire molding machine used therefor that can suppress the occurrence of cracking of the inner liner and prevent a decrease in the defective rate due thereto. The purpose is to do.

<1> is an inner liner rubber sheet having joint surfaces inclined and parallel to each other in the thickness direction at the front end and the rear end in the longitudinal section, the front end joint surface facing radially outward, Manufacture of a tire in which a circular inner liner rubber is formed by wrapping around a band drum so that the joining surface at the rear end faces radially inward and a part of the joining surface at the rear end overlaps radially outside the joining surface at the front end. In the method
After the inner liner rubber sheet is wound around a band drum and the rear end is pressed from the outside in the radial direction, a portion of the front end joining surface that does not overlap the rear end joining surface is crimped to the rear end from the inside in the radial direction. Press by machine ,
In the tire manufacturing method, the circumferential width at the tip of the pressing portion of the inner crimping machine is equal to or shorter than the length in the length direction of the joining surface at the tip of the inner liner rubber sheet .

  <2> is the same as in <1>, in which the winding outer diameter of the circumferential portion corresponding to the bonding surface at the front end and the bonding surface at the rear end of the annular inner liner rubber is the same as the winding outer diameter of the central portion in the length direction. This is a method for manufacturing a tire in which the inner liner rubber sheet is wound around a band drum.

<3> is an inner liner rubber sheet having joint surfaces inclined and parallel to each other in the thickness direction at the front end and the rear end in the longitudinal section, the front end joint surface facing radially outward, A band drum wound so that the joining surface at the rear end faces radially inward and a part of the joining surface at the rear end overlaps radially outside the joining surface at the tip, and an inner liner rubber sheet wound around the band drum An outer crimping machine that presses the rear end from the outside in the radial direction, and an inner crimping machine that presses a portion of the tip joining surface that does not overlap the rear end joining surface from the radially inner side to the rear end, On the peripheral surface of the band drum, an opening is formed through which a pressing portion that presses the tip joining surface of the inner crimping machine passes inward and outward in the radial direction .
In the tire molding machine, the circumferential width at the tip of the pressing portion of the inner crimping machine is equal to or shorter than the length in the length direction of the joining surface at the tip of the inner liner rubber sheet .

<4> is Oite to <3>, the pressing portion of the inner crimping machine is a tire molding machine, characterized in that it is storable configured inside the circle of the expanded diameter of the band drum.

  According to <1>, after the inner liner rubber sheet is wound around a band drum and the rear end is pressed from the outside in the radial direction, a portion of the front end joint surface that does not overlap the rear end joint surface is radiused to the rear end. Because it is pressed from the inside in the direction, even if there is a portion of the front end joint surface that does not overlap the rear end joint surface, it can be securely joined, and as a result, the vulcanized tire can be cracked. Absent.

  According to <2>, the winding outer diameter of the circumferential portion corresponding to the joining surface at the front end and the joining surface at the rear end of the annular inner liner rubber is the same as the winding outer diameter of the central portion in the length direction. Since the inner liner rubber sheet is wound around the band drum, the outer peripheral surface of the annular inner liner rubber can be made uniform in the circumferential direction without protruding only the joining surface portion, and thus each of the inner liner rubber sheets attached to the outer peripheral side. The outer peripheral surface of the member can also be made uniform in the circumferential direction, which can contribute to improvement of uniformity.

  According to <3>, the tire molding machine does not overlap with the rear end joint surface of the band drum that winds the inner liner rubber sheet, the outer pressure bonding machine that presses the rear end from the outside in the radial direction, and the front end joint surface. A portion is provided with an inner crimping machine that presses the rear end from the inside in the radial direction, and a pressing portion that presses the tip joining surface of the inner crimping machine is passed through the peripheral surface of the band drum inward and outward in the radial direction. Since the opening is formed, the effect described in <1> can be brought about similarly.

  According to <4>, the circumferential width of the tip of the pressing portion of the inner crimping machine is equal to or shorter than the length in the length direction of the joining surface at the tip of the inner liner rubber sheet. Only the narrow part including the part that does not overlap with the rear end joining surface is pressed against the rear end, and only the part that needs to be pressed can be efficiently pressed while suppressing the deformation of the other part.

  According to <5>, the pressing portion of the inner crimping machine is configured to be housed inside the circle of the expansion diameter of the band drum, so that the inner crimping machine can be easily attached to and detached from the drum. it can.

It is length direction sectional drawing of the inner liner rubber sheet for one tire used for this invention. It is sectional drawing which shows the state just before pressing the junction part of the cyclic | annular inner liner in the manufacturing method of the conventional tire with a crimping machine. It is sectional drawing which shows the state after pressing the junction part of the cyclic | annular inner liner in the manufacturing method of the conventional tire with a crimping machine. It is sectional drawing shown in the state before pressing the junction part of a cyclic | annular inner liner with a crimping machine in the manufacturing method of the tire which concerns on embodiment of this invention. It is sectional drawing shown in the state after pressing the junction part of a cyclic | annular inner liner with a crimping machine. It is sectional drawing shown in the state before pressing the junction part of a cyclic | annular inner liner with a crimping machine in the manufacturing method of the tire of the modification of embodiment which concerns on this invention.

  A tire manufacturing method according to an embodiment of the present invention and a tire molding machine used therefor will be described. FIG. 4 is a cross-sectional view showing a part of a tire molding machine for a tire according to the present invention. This tire molding machine includes a band drum 1 around which an inner liner rubber sheet 10 is wound, and a rear end 12 of the inner liner rubber sheet 10. The outer pressure bonding machine 2 that presses from the outside in the radial direction, and the inner side that presses the portion 13 of the joining surface 11a of the front end 11 of the inner liner rubber sheet 10 that does not overlap the joining surface 12a of the rear end 12 against the rear end 12 from the inner side in the radial direction. A crimping machine 3 is provided.

  The outer crimping machine 2 includes a pressing portion 4 that presses the rear end 12 from the outside in the radial direction, and a pressing cylinder 5 that moves the pressing portion 4 inward and outward in the radial direction and generates a pressing force when pressing the rear end 12. Similarly, the inner crimping machine 3 includes a pressing portion 6 that presses the tip 11 from the inside in the radial direction, and a pressing cylinder that moves the pressing portion 6 inward and outward in the radial direction and generates a pressing force when pressing the tip 11. 7 and configured.

  Further, the peripheral surface 1a of the band drum 1 is formed with an opening 8 through which the pressing portion 6 of the inner crimping machine 3 that presses the tip joining surface 11a passes inward and outward in the radial direction.

  In addition, the outer crimping machine 2 is arranged side by side in the width direction of the band drum 1 so that the rear end 12 of the inner liner rubber sheet 10 can be pressed over the entire width in the width direction. A plurality of inner liner rubber sheets 10 are arranged side by side in the width direction of the band drum 1 so that the tip 11 of the inner liner rubber sheet 10 can be pressed over the entire width.

  The annular inner liner rubber 20 is formed using such a tire molding machine as follows. That is, first, the front end of the pressing portion 6 of the inner crimping machine 3 is fixed at a radial position that matches the surface enveloping the outer periphery of the band drum 1, and then the corner portion 14 of the front end 11 of the inner liner rubber sheet 10 is fixed. The front end 11 of the inner liner rubber sheet 10 is positioned in the circumferential range corresponding to the outer peripheral side of the pressing portion 6 of the inner crimping machine 3 so that the joining surface 11a of the front end 11 faces radially outward. Paste to 1. Next, the band drum 1 is rotated around the center of rotation so that a part of the joining surface 12a of the rear end 12 overlaps the outside of the joining surface 11a of the front end 11 in the radial direction as shown in FIG. The inner liner rubber sheet 10 is wound around the band drum 1 to form the annular inner liner rubber 20.

  Next, the outer crimping machine 2 that has been retracted so as not to interfere with the winding of the inner liner rubber sheet 10 is disposed on the outer side in the radial direction of the portion corresponding to the rear end 12 of the annular inner liner rubber 20, and outer crimping is performed. The pressing cylinder 5 of the machine is actuated to move the pressing portion 4 attached to the tip thereof inward in the radial direction and press the rear end 12 inward in the radial direction.

  Thereafter, the pressing cylinder 7 of the inner crimping machine 3 is operated to move the pressing portion 6 attached to the tip thereof outward in the radial direction, and as shown in FIG. 4, the rear end joint surface of the front end joint surface 11a. A portion 13 that does not overlap 12a is pressed radially outward. The present invention is characterized in that the inner crimping machine 3 is used to press the portion 13 of the front joint surface 11a that does not overlap the rear joint surface 12a radially outward. By simply pressing the rear end 12 in the radial direction using 2, the remaining portion 13 of the front end joint surface 11 a that does not overlap the rear end joint surface 12 a can be reliably joined.

  In addition, by using the inner crimping machine 3 to press the portion 13 of the front end joint surface 11a that does not overlap the rear end joint surface 12a outward in the radial direction, conventionally, the joint surface has been pressed only from the outside. There is also an effect that it is possible to shorten the pressing time from the outside that has taken a long time to join 11a and 12a. When actually measured, the pressing time from the outside that took 3 to 5 seconds is 1.5 to 2.5. Could be shortened to seconds.

  In this case, as shown in FIG. 5, the circumferential width a of the tip of the pressing portion 6 of the inner crimping machine 3 is the same as the length b of the joining surface 11 a of the tip 11 of the inner liner rubber sheet 10. Or shorter than that, and only the narrow part including the part 13 that does not overlap the rear end joint surface 12a of the front end joint surface 11a is pressed against the rear end 12 while suppressing deformation of other parts. Only the part that needs to be pressed can be pressed efficiently.

  Here, as a modification of the present embodiment, as shown in FIG. 6, the winding outer diameter of the circumferential portion of the annular inner liner rubber 20 corresponding to the joining surface 11 a of the front end 11 and the joining surface 12 a of the rear end 12 is as follows. The inner liner rubber sheet 10 is preferably wound around the band drum 1 so as to be the same as the winding outer diameter of the central portion in the length direction. This is the inner pressure bonding before winding the inner liner rubber sheet 10 around the band drum 1. This can be realized by setting the radial position of the tip of the machine pressing portion 6 to the inner side by the thickness of the overlapping portion than in the previous embodiment.

  In this case, the outer peripheral surface of the annular inner liner rubber 20 can be made uniform in the circumferential direction without protruding only the joining surface portion, and as a result, the outer peripheral surface of each member attached to the outer peripheral side is also in the circumferential direction. It can be made uniform and can contribute to improvement of uniformity.

DESCRIPTION OF SYMBOLS 1 Band drum 1a Band drum peripheral surface 2 Outer crimping machine 3 Inner crimping machine 4 Pressing part of outer crimping machine 5 Pressing cylinder of outer crimping machine 6 Pressing part of inner crimping machine 7 Pressing cylinder of inner crimping machine 8 Opening of band drum DESCRIPTION OF SYMBOLS 10 Inner liner rubber sheet 11 Front end of inner liner rubber sheet 11a Joining surface of front end of inner liner rubber sheet 12 Rear end of inner liner rubber sheet 12a Joining surface of rear end of inner liner rubber sheet 13 Joining surface of front end and rear end Part that does not overlap with the joint surface 14 Corner of the tip of the inner liner rubber sheet 20 Annular inner liner rubber

Claims (4)

In the longitudinal section, an inner liner rubber sheet having joint surfaces inclined at the thickness direction and parallel to each other at the front end and the rear end, the front end joint surface facing radially outward, and the rear end joint surface In the method of manufacturing a tire in which an annular inner liner rubber is formed by wrapping around a band drum so that a part of the joining surface at the rear end overlaps the outside in the radial direction of the joining surface at the front end.
After the inner liner rubber sheet is wound around a band drum and the rear end is pressed from the outside in the radial direction, a portion of the front end joining surface that does not overlap the rear end joining surface is crimped to the rear end from the inside in the radial direction. Press by machine ,
A tire manufacturing method, characterized in that a circumferential width at a tip of a pressing portion of the inner crimping machine is equal to or shorter than a length in a length direction of a joining surface at a tip of an inner liner rubber sheet .   The inner liner rubber sheet is banded so that the winding outer diameter of the circumferential portion corresponding to the joining surface at the front end and the joining surface at the rear end of the annular inner liner rubber is the same as the winding outer diameter of the central portion in the length direction. The tire manufacturing method according to claim 1, wherein the tire is wound around a drum. In the longitudinal section, an inner liner rubber sheet having joint surfaces inclined at the thickness direction and parallel to each other at the front end and the rear end, the front end joint surface facing radially outward, and the rear end joint surface A band drum that is wound in such a way that the inner surface of the inner liner rubber sheet wound around the band drum is wound in such a manner that the inner surface is radially inward and a part of the rear end joint surface overlaps the outer radial direction of the front joint surface An outer crimping machine that presses from the outer side in the direction, and an inner crimping machine that presses a part of the tip joint surface that does not overlap with the rear joint surface from the inner side in the radial direction. In the inner crimping machine, an opening is formed through which a pressing portion that presses the tip joining surface passes radially inward and outward ,
A tire molding machine characterized in that the circumferential width at the tip of the pressing portion of the inner crimping machine is equal to or shorter than the length in the length direction of the joining surface at the tip of the inner liner rubber sheet . The tire molding machine according to claim 3 , wherein the pressing portion of the inner crimping machine is configured to be housed inside a circle having an expanded diameter of a band drum.

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