JP2016064508A - Press device for tire molding and tire molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of preventing properly, generation of defective articles due to crack of a clinch part, and deterioration of appearance quality due to bulge generation on a cushion part, in winding of a side wall rubber in a tire molding step.SOLUTION: A press device for tire molding comprises: a clinch roller for pressing a clinch part of a side wall rubber in which a cushion part and the clinch part are integrated and molded, in a tire constitution member which is wound around a cylindrical tire molding former which rotates. The press device for tire molding further comprises: brake means for applying rotation resistance to the clinch roller; and control means for controlling the brake means, in which, because the brake means applies rotation resistance to the clinch roller and presses the clinch part, the clinch part is extended and a joint amount on the clinch part is adjusted.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tire molding pressing device that presses a clinching portion of a sidewall rubber in a pneumatic tire molding process, and a tire molding method using the tire molding pressing device.

  In general, in the manufacturing process of a pneumatic tire, a raw tire is formed by winding various tire rubber members around a cylindrical tire-forming former and pressing them.

  FIG. 4 is a view schematically showing a conventional tire forming presser. As shown in FIG. 4, after a tire rubber material 102 such as an inner liner or a carcass ply is wound around a cylindrical tire molding former (not shown), the clinch portion 103a and the cushion portion 103b are integrally molded. Further, the raw rubber is molded by further winding and pressure-bonding the side wall rubber 103 cut to a fixed length.

  At this time, the tire rubber former 102 around which the tire rubber material 102 is wound is pasted on the tire rubber former 102 with the start end portion of the side wall rubber 103 cut into a fixed length, and the clinch roller 205 (free roller) of the tire molding press device 200 is used. The tire molding former is rotated while pressing the clinch portion 103a of the sidewall rubber 103. As a result, the clinch roller 205 is rotated along with the tire forming former, and the clinch portion 103a is sequentially pressed against the tire rubber material 102, and finally the winding start end and end portion of the clinch portion 103a are jointed.

  On the other hand, by pressing the cushion portion 103b with a pressure roller (not shown) that rotates in accordance with the rotating tire molding former, the cushion portion 103b is sequentially pressed against the tire rubber material 102, and finally the cushion portion 103b. The winding start end and end end are jointed. Note that reference numeral 201 in FIG. 4 denotes a holding cylinder that raises and lowers the clinch roller 205, 202 denotes a bearing, and 204 denotes a roller shaft.

JP 2011-102023 A

  However, in the case of the conventional tire molding method described above, a crack may occur in the joint portion of the clinch portion 103a after the joint. This is because the side wall rubber 103 is composed of a clinch portion 103a and a cushion portion 103b having different compositions, and a rubber material having a larger shrink amount than the cushion portion 103b is used for the clinch portion 103a. .

  That is, the clinched portion 103a in the side wall rubber 103 after cutting tends to shrink (3 to 5 mm) larger than the cushion portion 103b, so that the joint amount is insufficient in the joint portion of the clinched portion 103a, and cracking easily occurs. Become.

  For this reason, conventionally, the sidewall rubber 103 is cut and wound so as to be about 5 mm longer than the standard length in consideration of the shrinkage amount of the clinch portion 103a. In this case, the cushion amount is small. There is a possibility that the joint amount becomes too large at the portion 103b, and a bulge (bump) may occur after the tire is manufactured.

  As described above, in the conventional molding method, when the cushion portion 103b is made appropriate with respect to the joint amount of the sidewall rubber 103, the clinching portion 103a is cracked to cause a defective product, and the clinching portion 103a is made appropriate. There is a problem that the appearance quality may deteriorate due to the occurrence of bulges, and in any case, rework is required, which may reduce the production efficiency.

  Therefore, the present invention provides a technology capable of appropriately preventing the occurrence of defective products due to cracking of the clinch portion and the deterioration of the appearance quality due to the occurrence of bulges in the cushion portion when winding the sidewall rubber in the tire molding process. The issue is to provide.

  The inventor has intensively studied to solve the above-described problems, and found that the above-described problems can be solved by the invention described below, and has completed the present invention.

The invention described in claim 1
Of tire constituent members wound around a rotating cylindrical tire molding former, a tire molding pressing device provided with a clinch roller that presses the clinching portion of the sidewall rubber formed integrally with the cushion portion and the clinching portion. Because
Braking means for imparting rotational resistance to the clinch roller;
Control means for controlling the braking means,
A tire configured to adjust a joint amount in the clinching portion by extending the clinching portion by pressing the clinching portion while the braking means applies rotational resistance to the clinching roller. This is a pressing device for molding.

The invention described in claim 2
The braking means is an air brake attached to a roller shaft of the clinch roller;
2. The tire according to claim 1, wherein the control unit is an electropneumatic proportional valve that adjusts a rotation resistance applied to the clinch roller by controlling an air pressure supplied to the air brake. 3. This is a pressing device for molding.

The invention according to claim 3
It is used for a single molding machine in which both primary molding for bonding an inner liner and a carcass ply and secondary molding for bonding a sidewall rubber and a tread rubber are continuously performed on the tire molding former. The press device for molding a tire according to claim 1 or 2.

The invention according to claim 4
Using the tire molding press device according to any one of claims 1 to 3, the clinching portion of the side wall rubber in which the cushion portion and the clinching portion are integrally molded is pressure-bonded to the tire rubber material. A tire forming method,
In the tire molding method, the clinching portion is extended by pressing the clinching portion while applying a rotational resistance to the clinching roller by the braking means, and a joint amount in the clinching portion is adjusted.

The invention described in claim 5
The tire molding method according to claim 4, wherein a sidewall rubber having a width of 85 to 220 mm and a thickness of 15 mm or less is used as the sidewall rubber.

The invention described in claim 6
The tire molding according to claim 4 or 5, wherein the rotation resistance to the clinch roller is adjusted by the control means so that an amount of the clinch part after pressing is 7.5 mm or less. Is the method.

  According to the present invention, when winding the sidewall rubber in the tire molding process, it is possible to appropriately prevent the generation of defective products due to cracking of the clinch portion and the deterioration of the appearance quality due to the occurrence of bulges in the cushion portion. Can be provided.

It is a figure showing typically a pressing device for tire fabrication concerning one embodiment of the present invention. 1 is a schematic view of a tire molding presser according to an embodiment of the present invention. It is a graph which shows the relationship between the brake pressure provided to a clinching roller, and the amount of elongation of a clinching part. It is a figure which shows the conventional pressing device for tire shaping typically.

  Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

1. Overview of Tire Forming Pressing Device According to the Present Embodiment FIG. 1 is a diagram schematically showing the tire forming presser device according to the present embodiment.

  As shown in FIG. 1, a tire molding press device 1 according to the present embodiment is similar to a conventional tire molding press device, among tire constituent members wound around a rotating tire molding former (not shown). Further, a clinch roller 34 is provided that presses the clinch portion 6a of the sidewall rubber 6 in which the cushion portion 6b and the clinch portion 6a are integrally molded and rotates in accordance with the rotation of the tire molding former.

  However, the tire molding press device 1 according to the present embodiment includes an air brake 35 as a braking unit that imparts rotational resistance to the clinch roller 34 and a control unit (not shown) that controls the air brake 35. The air brake 35 is configured to adjust the joint amount in the clinching portion 6a by extending the clinching portion 6a by pressing the clinching portion 6a while applying rotational resistance to the clinching roller 34. It is different from the tire molding presser.

  As a result, as described below, in the tire molding process, when the sidewall rubber is wound around the tire molding former, each joint amount of the clinch portion and the cushion portion can be set to an appropriate value. Generation | occurrence | production of both the crack of the clinch part of wall rubber and the bulge in a cushion part can be prevented appropriately.

2. Specific Configuration of Tire Molding Pressing Device According to the Present Embodiment The tire molding presser device 1 according to the present embodiment will be described in detail. In the following description, a rubber member in which an inner liner, a carcass ply, and the like are stacked and a bead 5a is set is referred to as a “tire rubber material 5”.

  In the tire molding press device 1 according to the present embodiment, a roller shaft 33 is rotatably inserted into a rod portion 31 a of the device body 30 via a bearing 32. A clinching roller 34 is attached to one end of the roller shaft 33, and an air brake 35 is attached to the other end as braking means for applying rotational resistance to the clinching roller 34.

  The air brake 35 is preferably an air brake capable of obtaining a static friction torque of 9 N · m or more. As such an air brake, Asahi exhibits a static friction torque of 13.7 N · m at an air pressure of 0.6 MPa. Examples include BSM, 7X manufactured by Seiko Co., Ltd.

  Further, the apparatus main body 30 is provided with a pressing cylinder 31b, and the pressing force when the clinching roller 34 presses the clinching portion 6a is adjusted by moving the clinching roller 34 up and down via the rod portion 31a. Can do.

  FIG. 2 is a schematic view of the tire molding presser according to the present embodiment. As shown in FIG. 2, in the present embodiment, an electropneumatic proportional valve 36 is provided as a control means for controlling the air brake 35, and the air brake 35, the electropneumatic proportional valve 36, and the like are connected via an air supply pipe 37. Is connected. As this electropneumatic proportional valve 36, for example, ITV2050 (voltage type DC0 to 10V) manufactured by SMC Corporation is used.

  The electropneumatic proportional valve 36 is electrically connected to a PLC (Programmable Logic Controller) 41, and the PLC 41 is further connected to an IPC (Industrial PC) 42.

  The IPC 42 stores in advance specification information of a plurality of product tires (air pressure corresponding to the rubber composition of the clinching part), selects the specification information according to the product tire being manufactured, and transmits it to the PLC 41. The PLC 41 transmits a pressure adjustment signal (current having a voltage of DC 0 to 10 V) as an analog signal to the electropneumatic proportional valve 36 based on the specification information transmitted from the IPC 42.

  The electro-pneumatic proportional valve 36 controls the air brake 35 by adjusting the air pressure supplied to the air brake 35 based on the received pressure adjustment signal to control the air brake 35, thereby supporting the rubber composition of the clinching portion to be pressed. The rotation resistance thus applied can be applied to the clinch roller 34.

  When the tire molding former is rotated while pressing the clinch portion 6a with the clinch roller 34 to which such rotational resistance is applied, there is a deviation between the rotation of the tire molding former and the rotation of the clinch roller 34. A force along the circumferential direction of the tire forming former is applied to the clinch portion 6a wound around the former to extend the clinch portion 6a.

  And since the winding start end part of the clinching part 6a and the terminal part of the extended state are joined, even if it does not cut | disconnect the sidewall rubber 6 longer than a fixed length, the joint amount of the clinching part 6a Can be adjusted to an appropriate value (1 to 5 mm) according to the shrinkage amount of the clinching portion 6a. As a result, it is possible to appropriately prevent a crack from occurring in the clinch portion 6a after the joint.

  At this time, the cushion portion 6b of the sidewall rubber 6 is jointed by a cushion pressing roller (not shown) that rotates in accordance with the rotation of the tire molding former, as in the prior art. By cutting the sidewall rubber 6 with a standard length so that the amount becomes an appropriate value, the cushion portion 6b can be jointed in a state where the appropriate value is maintained. As a result, the occurrence of bulges in the cushion portion 6b can be prevented.

  As a result, according to the present embodiment, the joint amount of both the clinch portion 6a and the cushion portion 6b that are integrally molded is set to an appropriate value, and both the crack of the clinch portion 6a and the bulge in the cushion portion 6 are obtained. Generation | occurrence | production can be prevented and the frequency of rework for correcting the crack of the clinch part 6a and the bulge in the cushion part 6 can be reduced, and manufacturing efficiency can be improved.

  Although the shrink amount of the clinching portion 6a varies depending on the blending of the rubber constituting the clinching portion 6a, in the present embodiment, as described above, the specification information of a plurality of product tires is stored in the IPC 42 in advance. Since the rotation resistance applied to the clinch roller 34 is adjusted based on the spec information, the joint amount of the clinch portion 6a can be appropriately adjusted according to the type of product tire. .

  Moreover, in this Embodiment, the pressing force by which the clinching roller 34 presses the clinching part 6a can be adjusted by raising / lowering the clinching roller 34 using the pressing cylinder 31b. The pressing force at this time is preferably adjusted to 0.58 MPa. Thereby, the clinching part 6a can be sufficiently pressed and pressure-bonded to the tire rubber material 5.

  In addition, as the sidewall rubber 6 wound around the tire molding former, it is preferable to use a sidewall rubber having a width of 85 to 220 mm and a thickness of 15 mm or less.

  Further, the speed at which the clinching roller 34 rolls on the clinching portion 6a in order to press the clinching portion 6a is preferably 15 m / min.

  Depending on the type of product tire, the rotational resistance of the clinch roller by the braking means is preferably adjusted so that the elongation of the clinch portion 6a is 7.5 mm or less. Therefore, it is preferable to control the air pressure supplied to the air brake 35.

  Hereinafter, based on an Example, this invention is demonstrated concretely.

1. Investigation of Brake Pressure In this example, first, an appropriate value of the rotational resistance (brake pressure) applied to the clinch roller was examined in the tire molding presser according to the above-described embodiment.

(1) Investigation of shrinkage amount First, three types of sidewall rubbers with different clinch portion blends (blending A to blending C) are prepared, and the start and end portions of each sidewall rubber are butted together (joint (Amount = 0 mm) and left for a predetermined time, the gap generated in the clinch part after shrinkage was measured, and the shrinkage amount of the clinch part was investigated. The survey results are shown in Table 1. In Table 1, the shrinkage amount of the clinching portion is expressed as a negative joint amount.

(2) Investigation of the brake pressure and the amount of elongation of the clinching portion Using the tire molding pressing device 1 according to the above-described embodiment, the pressing force by the pressing cylinder 31b is set to 0.58 MPa, The clinching part 6 a was pressed with a clinching roller 34. At this time, the rotation resistance (brake pressure) applied to the clinch roller 34 by the air brake 35 is adjusted within a range of 0.1 to 0.5 MPa, and the elongation of the clinch portion 6a of the blend A to the blend C at each brake pressure. The amount (mm) was measured. Table 2 and FIG. 3 show the relationship between the brake pressure applied to the clinch roller and the amount of elongation of the clinch portion.

  As shown in Tables 1 and 2 and FIG. 3, in the case of using the rubber of compounding A having a shrinkage amount of 4 mm, in order to extend the clinch portion 6 a by 4 mm so that the shrinkage amount is offset, It can be seen that the pressure is preferably set to 0.27 Mpa.

  Further, in the case of Formulation B where the shrink amount is 5 mm, it is preferable to set the brake pressure to the clinch roller 34 to 0.5 Mpa in order to extend the clinch portion 6 a by 5 mm so that the shrink amount is offset. I understand. Similarly, in the case of Formulation C in which the shrink amount is 5.5 mm, it is found that it is preferable to set the brake pressure to 0.35 Mpa in order to extend the clinch portion 6 a by 5.5 mm. Preferred brake pressures for each formulation are shown in Table 3.

2. Green Tire Molding (1) Manufacturing Conditions A green tire was molded by applying a preferable brake pressure for each formulation obtained by the above test, and the occurrence of cracks in the clinch portion and bulges in the cushion portion was examined.

  Specifically, using the tire molding press device according to the above-described embodiment, a raw rubber was molded by pressing the sidewall rubber having the clinch portions of the blends A to C. At this time, as shown in Table 3, a preferable brake pressure for each formulation was applied to the clinch roller. In addition, 150 raw tires were molded for each formulation, and the cut length of the sidewall was set so that the joint amount of the clinch portion after pressing was 2 mm. Further, the pressing force by the pressing cylinder was set to 0.58 MPa.

(2) Result As a result of visually observing the molded raw tire, no crack was generated in the clinched portion after the joint in any of the side wall rubbers of Formulation A to Formulation C. Further, as a result of confirming the product tire obtained by vulcanizing the molded green tire, no bulge was found in the cushion portion. From this result, by pressing the clinching part while applying an appropriate brake pressure (rotational resistance) to the clinching roller 34, the joint amount of the clinching part is adjusted to an appropriate value, and the crack of the clinching part and the bulge of the cushion part are obtained. It was confirmed that it can be prevented.

  While the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments. Various modifications can be made to the above-described embodiment within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 1,200 Tire molding press device 5, 102 Tire rubber material 5a Bead 6, 103 Side wall rubber 6a, 103a Clinch portion 6b, 103b Cushion portion 30 Device body 31a Rod portion 31b, 201 Press cylinder 32, 202 Bearing 33, 204 Roller shaft 34, 205 Clinch roller 35 Air brake 36 Electropneumatic proportional valve 37 Air supply pipe 41 PLC
42 IPC

Claims (6)

Of tire constituent members wound around a rotating cylindrical tire molding former, a tire molding pressing device provided with a clinch roller that presses the clinching portion of the sidewall rubber formed integrally with the cushion portion and the clinching portion. Because
Braking means for imparting rotational resistance to the clinch roller;
Control means for controlling the braking means,
A tire configured to adjust a joint amount in the clinching portion by extending the clinching portion by pressing the clinching portion while the braking means applies rotational resistance to the clinching roller. Molding presser. The braking means is an air brake attached to a roller shaft of the clinch roller;
2. The tire according to claim 1, wherein the control unit is an electropneumatic proportional valve that adjusts a rotation resistance applied to the clinch roller by controlling an air pressure supplied to the air brake. 3. Molding presser. It is used for a single molding machine in which both primary molding for bonding an inner liner and a carcass ply and secondary molding for bonding a sidewall rubber and a tread rubber are continuously performed on the tire molding former. The press device for forming a tire according to claim 1 or 2. Using the tire molding press device according to any one of claims 1 to 3, the clinching portion of the side wall rubber in which the cushion portion and the clinching portion are integrally molded is pressure-bonded to the tire rubber material. A tire forming method,
A tire molding method comprising adjusting the joint amount in the clinching portion by extending the clinching portion by pressing the clinching portion while applying a rotational resistance to the clinching roller by the braking means.   The tire molding method according to claim 4, wherein a sidewall rubber having a width of 85 to 220 mm and a thickness of 15 mm or less is used as the sidewall rubber.   The tire molding according to claim 4 or 5, wherein the rotation resistance to the clinch roller is adjusted by the control means so that an amount of the clinch part after pressing is 7.5 mm or less. Method.

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