JP2012143908A - Method for manufacturing pneumatic tire, and green tire preheating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pneumatic tire capable of enhancing the quality of the tire after vulcanization molding while suppressing the unexpected deformation of the green tire, and a green tire preheating device.SOLUTION: The position of the splice part 10 of the outer peripheral surface of the green tire 2 is specified from the measuring result of a laser displacement meter 5 capable of running along the tire peripheral direction of the green tire 2 and the running distance thereof and a halogen heater 7 is moved toward the specified splice part 10 to heat the splice part 10 before vulcanization molding.

Description

  The present invention relates to a method for manufacturing a pneumatic tire and a preheating device for a green tire. More specifically, the spliced portion of a rubber member can be joined by suppressing the unintentional deformation of the green tire and preventing the air from being held in, and vulcanization molding. The present invention relates to a method for manufacturing a pneumatic tire capable of improving the quality of a later tire and a preheating device for a green tire.

  In the manufacturing process of a pneumatic tire, both ends of an unvulcanized rubber member wound around a tire molding drum are joined and molded into a cylindrical shape. This joining operation is performed by pressing the spliced portion where both ends of the rubber member are overlapped with a pressure roller or the like. However, it is difficult to sufficiently adhere the end portions of the splice part even if it is an unvulcanized rubber, simply by pressing with a pressure roller. For this reason, there is a problem in that air is entrapped in the splice part, and a failure occurs in which air remains in the vulcanized tire, which deteriorates the quality of the pneumatic tire.

  As a method for solving such a problem, for example, as described in Patent Document 1, an unvulcanized tire (green tire) before vulcanization is preheated to make the unvulcanized rubber more flexible. Thus, it is conceivable that the end portions of the splice portion are in close contact with each other without a gap.

  However, in the method disclosed in Patent Document 1, since the entire tire is heated, the green tire may be deformed into an unintended shape.

JP 2004-255633 A

  The objective of this invention is providing the manufacturing method of the pneumatic tire which can improve the quality of the tire after a vulcanization molding, and the preheating apparatus of a green tire, suppressing the deformation | transformation which the green tire does not intend.

  The pneumatic tire manufacturing method of the present invention that achieves the above object is a pneumatic tire manufacturing method for vulcanizing and molding a green tire having a splice portion of a rubber member on the outer peripheral surface, and detecting the displacement of the splice portion. The position of the splice part is specified by detection by means, and the heating means and the splice part are moved relative to each other based on the specified position data, and the splice part is heated by the heating means. Later, the green tire is put into a mold and vulcanized and molded.

  The green tire preheating device of the present invention that achieves the above object is a green tire preheating device for preheating a green tire having a splice portion of a rubber member on an outer peripheral surface, and a displacement detection means for detecting the splice portion. A heating means for heating the splice part; and a control means, the control means based on the position data for specifying the position of the splice part detected by the displacement detection means. The splice part is moved relative to each other to align the two.

  According to the pneumatic tire manufacturing method and the green tire preheating apparatus of the present invention, since only the splice portion of the green tire is heated, the green tire can be prevented from being deformed into an unintended shape. In addition, the fluidity of the rubber in the splice part is increased by heating, and the air entrapped in the splice part is easily removed during vulcanization molding, so that the quality of the tire after vulcanization molding can be improved.

  The splicing part is detected by moving the displacement detection means along the tire circumferential direction on the outer periphery of the green tire, and the position of the splicing part is specified from the measurement result of the displacement detection means and the travel distance thereof, and the specified splicing part is heated. It is desirable to heat the splice after moving the means and aligning.

  Alternatively, the splice portion is detected by the displacement detection means fixed at a predetermined distance near the outer peripheral surface of the green tire while the green tire is rotated by the rotation drive means, and the measurement result of the displacement detection means and the rotation angle of the rotation drive means The position of the splice is identified from the position of the green tire, and the splice is rotated after the green tire is rotated and moved to a heating means fixed at a predetermined distance near the outer peripheral surface of the green tire, and then the splice is heated. It is desirable to do.

  It is desirable to use a laser displacement meter as the displacement detection means and a halogen heater, an electric heater or an induction heating device as the heating means.

1 is a side view showing a preheating device for a green tire according to a first embodiment of the present invention. It is a top view of the preheating apparatus of the green tire of FIG. It is a top view which shows a state when moving a laser displacement meter to a start position. It is a top view which shows the state which is measuring the displacement of a tread surface with the laser displacement meter which drive | works. It is a top view which shows the state which aligned the halogen heater to the splice part. It is a side view which shows the case where the splice part of a side part is preheated with the preheating apparatus of the green tire of FIG. It is a side view which shows the preheating apparatus of the green tire which consists of the 2nd Embodiment of this invention. It is a top view of the preheating apparatus of the green tire of FIG. It is a top view which shows the state which is measuring the displacement of the tread surface rotated with a laser displacement meter. It is a top view which shows the state which aligned the splice part with the halogen heater. It is a side view which shows the case where the splice part of a side part is preheated with the preheating apparatus of the green tire of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show a green tire preheating apparatus according to a first embodiment of the present invention.

  This green tire preheating device (hereinafter simply referred to as “preheating device”) 1A includes a laser displacement meter 5 attached to a ring body 4 having a size surrounding the tread surface 3 of the green tire 2 and a robot arm 6. Is composed mainly of a halogen heater 7 which is rotatably attached to the tip of the head, and a controller 9 electrically connected to the laser displacement meter 5 and the robot arm 6 through signal lines 8a and 8b.

  The laser displacement meter 5 has a built-in drive device for traveling along the ring body 4 and a travel meter for recording the travel distance. The halogen heater 7 can be freely moved around the green tire 2 by the robot arm 6. The controller 9 can be composed of a personal computer with a central processing unit (CPU) incorporated therein. The laser displacement meter 5, the robot arm 6 and the controller 9 may be connected wirelessly instead of the signal lines 8a and 8b.

  A method for manufacturing a pneumatic tire using such a preheating device 1A will be described below.

  First, as a preparation stage, as shown in FIGS. 1 and 2, the green tire 2 and the ring body 4 are positioned so as to be coaxial, and the tread surface 3 is opposed to the laser displacement meter 5. On the tread surface 3 of the green tire 2, a splice portion 10 is formed in which end portions of band-shaped rubber members (cap tread rubber) constituting the tread portion are vertically stacked. Specifically, the tire conveying device 11 is operated, and the green tire 2 gripped on the inner diameter side by the plurality of gripping claws 12 is inserted into the inside of the fixed ring body 4 for alignment. To do. The tire transport device 11 is movably suspended on an arm (not shown) that extends to a vulcanization mold.

  Next, as shown in FIG. 3, the laser displacement meter 5 is caused to travel to the start position, and the built-in travel meter is reset. The halogen heater 7 is preferably retracted to an arbitrary place away from the ring body 4 by the robot arm 6 so as not to obstruct the travel of the laser displacement meter 5.

  Next, as shown in FIG. 4, the displacement (unevenness) of the tread surface 3 of the green tire 2 is measured while the laser displacement meter 5 travels along the ring body 4 for at least one round. At this time, the splice portion 10 has the largest peak and appears in the measurement data. The tire circumferential direction position of the splice unit 10 is specified from the measurement data and the travel distance data output from the travel meter of the laser displacement meter 5.

  Next, as shown in FIG. 5, the robot arm 6 moves the halogen heater 7 to the splice portion 10 whose position in the tire circumferential direction is specified and aligns it so as to face each other. Then, the splice unit 10 is heated to a temperature lower than the vulcanization temperature (for example, 60 to 120 ° C.) by the halogen heater 7.

  Finally, the heated green tire 2 is transported to the vulcanization molding die by the tire transport device 11 and used for the vulcanization molding process, and the laser displacement meter 5 is prepared for the next operation as shown in FIG. Return to the start position.

  In the vulcanization molding step, a pneumatic tire is manufactured by vulcanizing the green tire 2 in a mold at a predetermined pressure and time. In the present invention, it is preferable that the green tire 2 is immediately put into a mold and vulcanized immediately after the splice portion 10 is preheated.

  The steps according to FIGS. 3 to 5 are automatically performed by a program stored in the controller 9. The halogen heater 7 may be always turned on, but may be controlled by the controller 9 to be turned on / off.

  Thus, since only the splice part 10 is heated, the green tire 2 is not deformed into an unintended shape. Further, since the fluidity of the rubber in the splice part 10 is increased by heating, the air entrapped in the splice part is in close contact with the end parts of the splice part 10 without gaps, and is easily removed during vulcanization molding. Therefore, the quality of the tire after vulcanization molding can be improved.

  Furthermore, in this embodiment, since all the operations can be performed without contact with the green tire 2, the green tire 2 is not damaged. In addition, the splice portion 10 of the tread surface 3 is a portion that tends to be a rate-limiting portion of the vulcanization time because the gauge thickness is large, but the vulcanization time can be shortened by preheating the splice portion 10 in this way. This also has the advantage of improving tire productivity.

  In the above embodiment, the splice portion 10 of the tread surface 3 of the green tire 2 is targeted. However, as shown in FIG. 6, the green tire 2 and / or the ring body 4 is moved in the axial direction so that the green tire The splice part 14 which piled up and down the belt-shaped rubber member (side tread rubber) which comprises the 2 side parts 13 can also be made into object.

  It should be noted that two sets of preheating devices 1A corresponding to both side portions 13 and 13 or three sets of preheating devices 1A corresponding to the tread surface 3 are provided so as to overlap each other in the axial direction. May be. In that case, it is preferable to control each set of the laser displacement meter 5 and the robot arm 6 in order or simultaneously by one controller 9.

  7 and 8 show a green tire preheating apparatus according to the second embodiment of the present invention.

  The preheating device 1B includes an electric motor 15 that rotates the green tire 2 via the tire conveying device 11, a laser displacement meter 16 and a halogen heater 17 that are fixed so as to be located at a predetermined distance from the tread surface 3 of the green tire 2. And a controller 18 that is electrically connected to the electric motor 15, the laser displacement meter 16, and the halogen heater 17 through signal lines 8c, 8d, and 8e, respectively.

  The electric motor 15 has a built-in tachometer that records the phase (rotation angle) of the rotating shaft 19 that is detachably connected to the tire conveying device 11. The controller 18 can be composed of a personal computer or the like with a central processing unit (CPU) built therein, and the electric motor 15, the laser displacement meter 16, the halogen heater 17 and the controller 18 are connected to signal lines 8c and 8d. , 8e may be used instead of wireless connection.

  A method for manufacturing a pneumatic tire using such a preheating device 1B will be described below.

  First, as a preparatory stage, the rotating shaft 19 of the electric motor 15 is connected to the tire conveying device 11, and the tread surface 3 of the green tire 2 is placed at a predetermined distance from the laser displacement meter 16 and the halogen heater 17 as shown in FIG. Position them so that they face each other. At the same time, the tachometer built in the electric motor 15 is reset. Further, the halogen heater 17 is turned off. The tread surface 3 of the green tire 2 is formed with a splice portion 10 in which cap tread rubber ends are stacked one above the other. The relative positional relationship between the laser displacement meter 16 and the halogen heater 17 is not particularly limited, but is fixed at positions facing each other across the green tire 2 in order to facilitate alignment with the green tire 2. It is preferable to do.

  Next, as shown in FIG. 9, the motor 15 is driven to rotate the green tire 2 at least once, and the unevenness of the tread surface 3 of the green tire 2 is measured by the laser displacement meter 16. At this time, the splice portion 10 has the largest peak and appears in the measurement data. From the measurement data and the rotation angle data output from the tachometer of the electric motor 15, the tire circumferential direction position of the splice unit 10 is specified.

  Next, as shown in FIG. 10, the green tire 2 is rotated by the electric motor 15, and the splice part 10 whose tire circumferential direction position is specified is moved to the halogen heater 17 and aligned so as to face each other. Then, the halogen heater 17 is turned on to heat the splice unit 10 to a temperature lower than the vulcanization temperature (for example, 60 to 120 ° C.). Finally, after the rotary shaft 19 of the electric motor 15 and the tire transport device 11 are separated, the heated green tire 2 is transported to the vulcanization molding die by the tire transport device 11 and used for the vulcanization molding process. .

  In the vulcanization molding step, a pneumatic tire is manufactured by vulcanizing the green tire 2 in a mold at a predetermined pressure and time. In the present invention, it is preferable that the green tire 2 is immediately put into a mold and vulcanized immediately after the splice portion 10 is preheated.

  The steps according to FIGS. 9 and 10 are automatically performed by a program stored in the controller 18.

  Thus, since only the splice part 10 is heated, the green tire 2 is not deformed into an unintended shape. Further, since the fluidity of the rubber in the splice part 10 is increased by heating, the air entrapped in the splice part is in close contact with the end parts of the splice part 10 without gaps, and is easily removed during vulcanization molding. Therefore, the quality of the tire after vulcanization molding can be improved.

  Furthermore, in this embodiment, since all the operations can be performed without contact with the green tire 2, the green tire 2 is not damaged. In addition, the splice portion 10 of the tread surface 3 is a portion that tends to be a rate-limiting portion of the vulcanization time because the gauge thickness is large, but the vulcanization time can be shortened by preheating the splice portion 10 in this way. This also has the advantage of improving tire productivity.

  In the above embodiment, the splice portion 10 of the tread surface 3 of the green tire 2 is targeted. However, as shown in FIG. 11, the side portion 13 of the green tire 2 is moved by moving the green tire 2 in the axial direction. The splice part 14 which piled up the side tread rubber which comprises may be made into object.

  In addition, you may make it provide two sets of preheating apparatuses 1B corresponding to both the side parts 13 and 13, or three sets of preheating apparatuses 1B corresponding to the tread surface 3, respectively, up and down in an axial direction. . In such a case, it is preferable to control each set of electric motor 15, laser displacement meter 16 and halogen heater 17 in order or simultaneously by one controller 18.

  In any of the above embodiments, an electric heater can be used instead of the halogen heater 17. In addition, when a metal is used for a component inside the tire such as a belt layer, an induction heating device can be used.

  Furthermore, in any of the above-described embodiments, not only a non-contact type heating unit but also a contact type heating unit such as a heating plate or a thermocompression roller that contacts the splice parts 10 and 14 can be used. When a heating plate is used, the splice parts 10 and 14 are heated while being pressed by the heating plate. When a thermocompression-bonding roller is used, the splices 10 and 14 are rolled and pressed while being heated. In the latter case, it is appropriate to use a core that supports the splices 10 and 14 from the inside of the tire as necessary.

  A case in which only the splice portion 10 of the tread surface 3 is heated using the preheating device 1A according to the first embodiment for the green tires 2 (the number of tires: 10,000) of pneumatic tires having a tire size of 145R12 (Example 1) 2) The number of green tires deformed into an unintended shape in a case where the entire tire is heated (Comparative Example 1) and a case where the heating is not performed (Comparative Example 2), and a failure in which air remains after vulcanization molding The number of generated pneumatic tires is shown in Table 1, respectively.

  For each case, the blow point (BP) of the tire at the time of vulcanization molding was also evaluated, and the results are shown in Table 1. The blow point means the minimum vulcanization time during which no bubble is observed in the tire rubber when the pressure is released after vulcanization molding.

  From the results of Table 1, it can be seen that in the case where only the splice part is heated (Example), the number of green tires 2 deformed into an unintended shape can be reduced to zero, unlike the case where the entire tire is heated (Comparative Example 1). . In addition, the occurrence of failures in which air remains due to heating can be reduced. In particular, the first embodiment in which the heating temperature of the splice unit 10 is high is effective in shortening the vulcanization time while suppressing the occurrence of failures in which air remains. It turns out that it is.

1A, 1B Preheating device 2 Green tire 3 Tread surface 4 Ring body 5, 16 Laser displacement meter 7, 17 Halogen heater 8a-8e Signal line 9, 18 Controller 10, 14 Splice unit 11 Tire transport device 12 Grip claw 13 Side portion 15 Electric motor 19 Rotating shaft

Claims (8)

A method for producing a pneumatic tire for vulcanizing a green tire having a splice portion of a rubber member on an outer peripheral surface,
The splice portion is detected by the displacement detection means to identify the position of the splice portion, and based on the specified position data, the heating means and the splice portion are relatively moved to align both, and the heating means A method for producing a pneumatic tire, comprising: heating the splice portion and then vulcanizing and molding the green tire into a mold.   The displacement detection means is moved along the tire circumferential direction on the outer periphery of the green tire to detect the splice part, and the position of the splice part is specified from the measurement result of the displacement detection means and the travel distance thereof, and the specification The method for manufacturing a pneumatic tire according to claim 1, wherein the splicing portion is heated after the heating means is moved to the spliced portion and aligned.   While the green tire is rotated by the rotation drive means, the splice portion is detected by a displacement detection means fixed at a predetermined distance in the vicinity of the outer peripheral surface of the green tire, and the measurement result of the displacement detection means and the rotation drive means The position of the splice portion is specified from the rotation angle of the green tire, the green tire is rotated, and the specified splice portion is moved to a heating means fixed at a predetermined distance near the outer peripheral surface of the green tire for alignment. The method for manufacturing a pneumatic tire according to claim 1, wherein the splice portion is heated after the heating. A preheating device for a green tire for preheating a green tire having a splice portion of a rubber member on an outer peripheral surface,
Displacement detecting means for detecting the splice part, heating means for heating the splice part, and control means,
The control means moves the heating means and the specified splice part relative to each other based on position data specifying the position of the splice part detected by the displacement detection means, and aligns the two. Green tire preheating device. While holding the displacement detection means movably along the tire circumferential direction of the green tire, and holding the heating means movably in the vicinity of the outer periphery of the green tire,
5. The control unit according to claim 4, wherein the control unit specifies the position of the splice unit from the measurement result of the displacement detection unit and the travel distance thereof, and moves the heating unit to the specified splice unit to align with the splice unit. The described green tire preheating device. The displacement detection means and the heating means are respectively fixed at predetermined distances in the vicinity of the outer peripheral surface of the green tire, and a rotation drive means for rotating the green tire is provided,
The control means specifies the position of the splice part from the measurement result of the displacement detection means and the rotation angle of the rotation drive means, rotates the green tire by the rotation drive means, and determines the specified splice part. The preheating device for a green tire according to claim 4, wherein the preheating device is moved to the heating means and aligned with the heating means.   The green tire preheating device according to any one of claims 4 to 6, wherein the displacement detecting means is a laser displacement meter.   The preheating device for a green tire according to any one of claims 4 to 7, wherein the heating means is a halogen heater, an electric heater or an induction heating device.

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