JP2021074890A - Manufacturing method and manufacturing system for pneumatic tire - Google Patents

Abstract

To provide a manufacturing method and a manufacturing system for a pneumatic tire for enabling centering of a tread rubber while suppressing deformation of the tread rubber.SOLUTION: A manufacturing method for a pneumatic tire comprises of conveying a tread rubber placed on a conveyor with a first end of a width direction of the tread rubber as a front, aligning a center line of the tread rubber with a first predetermined position, by receiving the first end of the tread rubber conveyed by the conveyor on a first receiving surface of an elongated member, and transferring the tread rubber with a center line aligned at the first predetermined position by the long member from the conveyor to a tray by constant operation of a transfer device.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a method and a manufacturing system for a pneumatic tire.

Pneumatic tires include a first assembly called a first case in which a plurality of tire components such as a car vulcan ply are molded, and a second assembly called a second case in which a plurality of tire components such as a tread rubber and a belt are molded. It is manufactured by molding into one raw tire and then vulcanizing the raw tire by heating and pressurizing in the mold.

Patent Document 1 discloses, as one of the molding methods of the second case, a method of supplying tread rubber from above the drum to a belt molded in an annular shape on the drum and winding the tread rubber around the belt on the drum. ing. Patent Document 1 discloses that in order to wind the tread rubber with high accuracy, a pair of guide rollers are arranged on both sides in the width direction of the tread rubber, and the tread rubber is pressed by the pair of guide rollers to center the tread rubber. ing.

In the tire manufacturing process, it is required to align the center line of the tread rubber at a predetermined position (centering). However, the tread rubber centering method disclosed in Patent Document 1 is a method of pressing the tread rubber supplied to the drum and under tension from both sides in the width direction. This method may result in deformation of the tread rubber. In particular, it cannot be used in manufacturing tires with high demand for uniformity.

Japanese Unexamined Patent Publication No. 2014-104589

The present disclosure provides a method and a manufacturing system for a pneumatic tire that enables centering of the tread rubber while suppressing deformation of the tread rubber.

The method for manufacturing a pneumatic tire according to the present disclosure is to transport the tread rubber placed on the conveyor with the first end in the width direction of the tread rubber at the head, and to convey the tread rubber mounted on the conveyor. By receiving the first end on the first receiving surface of the elongated member, the center line of the tread rubber is aligned with the first predetermined position, and the center line is aligned with the first predetermined position by the elongated member. The tread rubber in a state of being aligned with the tire is transferred from the conveyor to the tray by a constant operation of the transport device.

The pneumatic tire manufacturing system of the present disclosure has a conveyor that conveys the mounted tread rubber with the first end in the width direction of the tread rubber at the head, and a first receiving surface, and conveys the tread rubber by the conveyor. By receiving the first end of the tread rubber on the first receiving surface, the elongate member aligns the center line of the tread rubber with the first predetermined position, and the elongate member makes the center line. The tread rubber in a state of being aligned at the first predetermined position is provided with a transport device for transferring the tread rubber from the conveyor to the tray by a constant operation.

The figure which shows the molding process of the second case The figure which shows the process of forming a raw tire by connecting a first case and a second case. Side view schematically showing the manufacturing system Top view schematically showing the manufacturing system Side view showing the operation of the transport device in the manufacturing system Cross-sectional view of A1-A1 site in FIG. Explanatory side view of switching between the first operation and the second operation of the conveyor Flowchart showing the processing performed by the manufacturing system

<Manufacturing method of pneumatic tires>
Pneumatic tires are manufactured by laminating a plurality of tire components to manufacture a raw tire T3 (see FIG. 2) and vulcanizing the raw tire T3 by heating and pressurizing it in a mold. ,including. The raw tire manufacturing method includes a step of molding the first assembly T1 (see FIG. 2), which is also called a first case, a step of molding a second assembly T2 (see FIGS. 1 and 2), which is also called a second case, and a first assembly. It comprises a step of inflating T1 and combining it with a second assembly T2 to obtain a raw tire T3 (see FIG. 2).

<Molding of the first assembly T1 (first case)>
In the step of molding the first assembly T1, a tire component (not shown) such as an inner liner rubber and a carcass is wound around a molding drum (not shown). After that, bead fillers (not shown) and bead cores (not shown) are arranged at both ends of the carcass, and the carcass is wound up by inflating the bladder (not shown). Next, a sidewall rubber (not shown) is wound to obtain a first assembly T1 (first case). The description here is an example, and the method of manufacturing the first assembly T1 is not limited to the method described. The first assembly T1 can be molded by other methods.

<Molding of the second assembly T2 (second case)>
The process of molding the second assembly T2 (second case) will be described with reference to FIG. As shown in FIG. 1, after winding a tire component such as a belt 20 around a belt drum 10, a tread rubber 21 is wound around the tire to obtain a second assembly T2 (second case). As shown in FIG. 1, the tread rubber 21 is placed on the tray 30, and the tread rubber 21 on the tray 30 and the belt 20 at the lower part of the belt drum 10 are brought into contact with each other to rotate the belt drum 10. By moving the tray 30, the tread rubber 21 is wound around the belt 20. As shown in FIG. 1, in the construction method in which the tread rubber 21 is supplied from below the belt drum 10, the tread rubber 21 is deformed by its own weight as compared with the construction method in which the tread rubber 21 is supplied from above the belt drum 10. Can be suppressed. This method is particularly suitable for manufacturing tires that require high uniformity.

<Combining the first assembly T1 and the second assembly T2>
As shown in FIG. 2, in the molding apparatus 11, the second assembly T2 is arranged on the outer circumference of the first assembly T1, and the beads of the first assembly T1 are brought close to each other while inflating the first assembly T1 with a bladder, and the stitcher is used. The second assembly T2 is pressed against the first assembly T1 and the second assembly T2 and the first assembly T1 are joined to form the raw tire T3.

<Transport process of tread rubber 21 to tray 30>
The tread rubber 21 is extruded from an extruder (not shown) and molded. After that, the tread rubber 21 is conveyed to the top of the tray 30 through a processing step such as a cooling step. Hereinafter, the transfer process of the tread rubber 21 to the tray 30 in the method for manufacturing a pneumatic tire will be described.

<Manufacturing system>
FIG. 3 is a side view schematically showing a manufacturing system (conveyance system). FIG. 4 is a plan view schematically showing a manufacturing system (conveyance system). As shown in FIGS. 3 and 4, the pneumatic tire manufacturing system of the present embodiment includes a conveyor 4, a long member 50, and a transfer device 60.

The conveyor 4 conveys the mounted tread rubber 21 with the first end 21a of the width direction WD of the tread rubber 21 at the head. Specifically, the conveyor 4 has a plurality of endless bands 40. Each endless band 40 extends parallel to the transport direction TD (X direction) of the tread rubber 21. The plurality of endless bands 40 are arranged at intervals in a direction (Y direction) orthogonal to the transport direction TD. Each endless band 40 is supported by a band support element 41 for supporting the endless band 40. The endless band 40 is rotated by rotating the band support element 41 in a predetermined first direction, and the tread rubber 21 placed on the endless band 40 is conveyed along the transfer direction TD. In the present embodiment, the endless band 40 is an endless chain and the band support element 41 is a sprocket, but the present invention is not limited thereto. For example, the endless band 40 may be an endless belt, and the band support element 41 may be a belt pulley. Further, the conveyor 4 has a plurality of endless bands 40, but is not limited thereto. For example, it may be a single belt conveyor.

The elongated member 50 has a first receiving surface 51. The elongated member 50 aligns the center line C1 of the tread rubber 21 with the first predetermined position PP1 by receiving the first end 21a of the tread rubber 21 conveyed by the conveyor 4 on the first receiving surface 51. The first predetermined position PP1 is a position relative to the transfer device 60 at the position where the tread rubber 21 is picked up. FIG. 4 shows that the center line C1 of the tread rubber 21 is inclined with respect to the transport direction TD. Even in such an inclined posture, the posture is corrected by the elongated member 50. The elongated member 50 is supported by two support portions 53 provided on the base 52. In the present embodiment, the number of support portions 53 is two, but the number of support portions 53 can be one or more. As shown in FIG. 3, the elongated member 50 is arranged above the plurality of endless bands 40. As shown in FIG. 4, the elongated member 50 straddles a plurality of endless bands 40 in a plan view.

The two support portions 53 of the present embodiment are configured so that the amount of protrusion from the base 52 can be changed independently. The amount of protrusion is determined by the number of rotations of the motor for moving the support portion 53. With this configuration, at least one of the positions or inclinations of the elongated member 50 with respect to the conveyor 4 can be adjusted. If the protrusion amounts of the first support portion and the second support portion of the two support portions 53 are changed, the position of the elongated member 50 is changed, and the protrusion amounts of the first support portion and the second support portion are different. For example, the inclination of the elongated member 50 is changed. When the width of the tread rubber 21 is input to the manufacturing system, the elongated member 50 is automatically adjusted according to the width. However, since the tread rubber 21 is a rubber member, its dimensions vary depending on environmental conditions (change in room temperature due to seasonal factors, change in cooling degree, etc.). This adjustment is performed during the initial inspection.

FIG. 6 is a cross-sectional view of the A1-A1 site in FIG. FIG. 6 shows only the elongated member 50 and the endless band 40. As shown in the figure, the bottom of the elongated member 50 has a plurality of first bottoms 50a facing each endless band 40 and at least one second bottom 50b. At least one second bottom 50b is located between the plurality of endless bands 40 in a plan view and does not face any of the plurality of endless bands 40. At least one second bottom 50b has a protrusion 54 protruding below the first bottom 50a. If the bottom surface of the protrusion 54 is below the top surface of the endless band 40, it is possible to effectively prevent the tread rubber 21 from entering between the elongated member 50 and the endless band 40, which is preferable. Of course, the protrusion amount of the protrusion 54 can be arbitrarily changed. For example, the bottom surface of the protrusion 54 may be above the top surface of the endless band 40.

As shown in FIG. 5, the conveyor 60 trays the tread rubber 21 in a state where the center line C1 is aligned with the first predetermined position PP1 by the elongated member 50 from the conveyor 4 by a constant operation. Transfer onto 30. As shown in FIG. 5, the transport device 60 is configured to perform a constant operation. The constant operation means that the moving distance MD1 (driving amount) of the transport device 60 is constant, as shown in FIG. As a result, the center line C1 of the tread rubber 21 transferred to the tray 30 coincides with the second predetermined position PP2, which is a position relative to the tray 30. The second predetermined position PP2 may be, for example, the center of the tray 30 in the width direction WD.

The conveyor 4 may be configured to always convey the tread rubber 21 at a constant speed, but is preferably configured as follows. As shown in FIG. 7, the conveyor 4 is configured to be able to execute the first operation MV1 and the second operation MV2. The first operation MV1 is an operation in which the conveyor 4 conveys the tread rubber 21. The second operation MV2 is an operation after the first operation MV1 and stops the conveyor 4 after the first end 21a of the tread rubber 21 is brought into contact with the first receiving surface 51 of the elongated member 50 by the conveyor 4. It is an operation. The transfer speed of the conveyor 4 in the second operation MV2 is slower than the transfer speed of the conveyor 4 in the first operation MV1. In order to realize the first operation MV1 and the second operation MV2, the system is configured as follows in the present embodiment. A sensor 55 for detecting the presence or absence of the tread rubber 21 at a position separated from the first receiving surface 51 of the elongated member 50 by a predetermined distance is provided. If the sensor 55 does not detect the tread rubber 21, the conveyor 4 conveys the tread rubber 21 at the first speed. When the sensor 55 detects the tread rubber 21, the transport speed of the conveyor 4 is switched to the second speed, which is slower than the first speed. The conveyor 4 stops the transport of the tread rubber 21 when a predetermined time elapses from the time when the sensor 55 detects the tread rubber 21 or when the tread rubber 21 is transported by a predetermined distance. The time point for switching from the first operation MV1 to the second operation MV2 is preferably before the first end 21a of the tread rubber 21 comes into contact with the first receiving surface 51 of the elongated member 50. In this way, the lead time can be shortened by the conveyor 4 executing the first operation MV1. Further, when the conveyor 4 executes the second operation MV2, it is possible to prevent the tread rubber 21 from being deformed when the first end 21a of the tread rubber 21 comes into contact with the first receiving surface 51 of the elongated member 50. It becomes.

As shown in FIG. 3, the angle θ1 of the first end 21a of the tread rubber 21 is preferably 21 degrees or more and 27 degrees or less in the cross section passing through the width direction WD and the thickness direction of the tread rubber 21. When the angle θ1 of the first end 21a is less than 21 degrees, the tread rubber 21 easily enters between the conveyor 4 (endless band 40) and the elongated member 50. When the angle θ1 of the first end 21a exceeds 27 degrees, it is formed between the tread rubber 21 and the sidewall rubber when the tread rubber 21 and the sidewall rubber are contacted and molded as shown in FIG. The step becomes noticeable.

<Manufacturing system operation>
The operation of the manufacturing system will be described with reference to FIG. First, in step ST1, the conveyor 4 conveys the tread rubber 21 placed on the conveyor 4. The first end 21a of the width direction WD of the tread rubber 21 is the head. This operation is the first operation MV1 of the conveyor 4, and the conveyor 4 conveys at the first transfer speed. In the next step ST2, the center line C1 of the tread rubber 21 is received by the first receiving surface 51 of the elongated member 50 by receiving the first end 21a of the tread rubber 21 conveyed by the conveyor 4 at the first predetermined position PP1. Align to. This operation is the second operation MV2 of the conveyor 4, and the conveyor 4 conveys at a second transfer speed slower than the first transfer speed. In the next step ST3, the tread rubber 21 in a state where the center line C1 is aligned with the first predetermined position PP1 by the elongated member 50 is transferred from the conveyor 4 to the tray 30 by a constant operation of the transfer device 60.

As described above, the method for manufacturing the pneumatic tire of the present embodiment is
The tread rubber 21 mounted on the conveyor 4 is conveyed with the first end 21a of the width direction WD of the tread rubber 21 at the head (ST1).
By receiving the first end 21a of the tread rubber 21 conveyed by the conveyor 4 on the first receiving surface 51 of the elongated member 50, the center line C1 of the tread rubber 21 is aligned with the first predetermined position PP1 (ST2). When,
The tread rubber 21 in a state where the center line C1 is aligned with the first predetermined position PP1 by the elongated member 50 is transferred from the conveyor 4 to the tray 30 by a constant operation of the transfer device 60 (ST3).
including.

The manufacturing system of this embodiment is
A conveyor 4 that conveys the mounted tread rubber 21 with the first end 21a of the width direction WD of the tread rubber 21 at the head.
A length that aligns the center line C1 of the tread rubber 21 with the first predetermined position PP1 by receiving the first end 21a of the tread rubber 21 that has the first receiving surface 51 and is conveyed by the conveyor 4 on the first receiving surface 51. Scale member 50 and
A transport device 60 that transfers the tread rubber 21 in a state where the center line C1 is aligned with the first predetermined position PP1 by the elongated member 50 from the conveyor 4 to the tray 30 by a constant operation.
To be equipped.

According to this configuration, by receiving the first end 21a of the width direction WD of the tread rubber 21 conveyed to the conveyor 4 by the first receiving surface 51 of the elongated member 50, the center line C1 of the tread rubber 21 becomes the first. 1 Aligned to a predetermined position PP1. Since the tread rubber 21 in a state where the center line C1 is aligned with the first predetermined position PP1 is transferred from the conveyor 4 onto the tray 30 by a constant operation, the center line C1 of the tread rubber 21 on the tray 30 is at the first predetermined position. It will be in a state where it is aligned at the position corresponding to PP1.
Therefore, when the tread rubber 21 is wound around the annular belt while being placed on the tray 30 in the subsequent process, it is possible to suppress or prevent the occurrence of defective products due to misalignment.

Like the method or system of the present embodiment, the conveyor 4 has a plurality of endless bands 40 extending in the transport direction TD of the tread rubber 21 and arranged at intervals in a direction orthogonal to the transport direction TD, and has a length. The elliptical member 50 is arranged above the plurality of endless bands 40 and straddles the plurality of endless bands 40 in a plan view, and the bottom of the elongated member 50 is a plurality of th-orders facing each endless band 40. It has one base 50a and at least one second bottom 50b located between the plurality of endless bands 40 in a plan view and does not face any of the plurality of endless bands 40, and at least one second bottom 50b. Preferably has a protrusion 54 protruding below the first bottom 50a.

Since the endless band 40 and the elongated member 50 cannot come into contact with each other, there is a limit to reducing the gap between the first bottom 50a of the elongated member 50 and the endless band 40. However, since the second bottom 50b has a protrusion 54 protruding below the first bottom 50a, the long member 50 and the long member 50 are endless while avoiding contact between the endless band 40 and the long member 50. It is possible to suppress or prevent the tread rubber 21 from entering between the bands 40. Therefore, the misalignment of the tread rubber 21 can be suppressed or prevented, and the occurrence of defective products can be suppressed or prevented.

Like the system of the present embodiment, it is preferable that the elongated member 50 is configured so that at least one of the positions or inclinations with respect to the conveyor 4 can be adjusted.

The tread rubber 21 can be adjusted according to the molding accuracy, the misalignment of the tread rubber 21 can be suppressed or prevented, and the occurrence of defective products can be suppressed or prevented.

As in the method of the present embodiment, the first operation MV1 in which the conveyor 4 conveys the tread rubber 21 and the operation after the first operation MV1 in which the first end 21a of the tread rubber 21 is elongated by the conveyor 4. The transfer speed of the conveyor 4 in the second operation MV2 includes the second operation MV2 that stops the conveyor 4 after being brought into contact with the first receiving surface 51 of the member 50, and the transfer speed of the conveyor 4 in the first operation MV1 is higher than the transfer speed of the conveyor 4 in the first operation MV1. Is also preferable to be slow.
Like the system of the present embodiment, the conveyor 4 is an operation after the first operation MV1 for conveying the tread rubber 21 and the first operation MV1 and has the first end 21a of the tread rubber 21 as a long member 50. The second operation MV2 is configured to bring the conveyor 4 into contact with the first receiving surface 51 to stop the conveyor 4, and the transfer speed of the conveyor 4 in the second operation MV2 is the same as that of the conveyor 4 in the first operation MV1. It is preferably slower than the transport speed.

In this way, even if the transfer speed of the conveyor 4 in the first operation MV1 is set to a high speed in order to shorten the lead time, the transfer speed of the second operation MV2 is slower than that of the first operation MV1. Therefore, it is possible to prevent the tread rubber 21 from coming into contact with the elongated member 50 at high speed and deforming the tread rubber 21.

As in the present embodiment, the angle θ1 of the first end 21a in the cross section passing through the width direction WD and the thickness direction of the tread rubber 21 is preferably 21 degrees or more and 27 degrees or less.

If the angle θ1 of the first end 21a is less than 21 degrees, the tread rubber 21 is likely to enter between the conveyor 4 and the elongated member 50, and the tread rubber 21 is likely to be misaligned. When the angle θ1 of the first end 21a exceeds 27 degrees, the step formed between the tread rubber 21 and the sidewall rubber becomes conspicuous when the tread rubber 21 and the sidewall rubber are contacted and molded. Become.
Therefore, within the range of the angle θ1, the misalignment of the tread rubber 21 and the aesthetic appearance of the outer surface of the tire can be ensured.

Although the embodiments of the present disclosure have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present disclosure is shown not only by the description of the above-described embodiment but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment. The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present disclosure.

It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment.

As the molding method of the second case (second assembly T2), not the molding method shown in FIG. 2, but the molding method of supplying the tread rubber from above the belt drum to the belt drum, the servicer and the belt for supplying the tread rubber There is a gap between it and the drum. The tread rubber may be deformed by the weight of the tread rubber, and the tread rubber may be deformed by applying tension to the tread rubber by the belt drum. Deformation of the tread rubber causes a change in the weight distribution, so it is not a preferable construction method for manufacturing tires with high demand for uniformity. From the viewpoint of uniformity, a method for manufacturing the second assembly T2 using the tray 30 is preferable. The molding method of the second assembly T2 using the tray 30 does not immediately attach the rubber extruded from the extruder. Since the tread rubber 21 cools with the tread rubber 21 placed on the tray 30, even if the tread rubber 21 tries to shrink, it sticks to the tray 30, so that abnormal shrinkage can be prevented and misalignment can be suppressed.

21 ... Tread rubber, 21a ... 1st end, 30 ... Tray, 4 ... Conveyor, 40 ... Endless band, 50 ... Elongated member, 50a ... 1st bottom, 50b ... 2nd bottom, 51 ... 1st receiving surface, 54 ... protrusion, 60 ... transport device, C1 ... center line, PP1 ... first predetermined position, TD ... transport direction, WD ... tread rubber width direction, MV1 ... first operation, MV2 ... second operation, θ1 ... angle

Claims (9)

The tread rubber placed on the conveyor is conveyed with the first end in the width direction of the tread rubber at the beginning.
By receiving the first end of the tread rubber conveyed by the conveyor on the first receiving surface of the elongated member, the center line of the tread rubber is aligned with the first predetermined position.
The tread rubber in a state where the center line is aligned with the first predetermined position by the elongated member is transferred from the conveyor to the tray by a constant operation of the transport device.
How to make pneumatic tires, including. The conveyor has a plurality of endless bands extending in the transport direction of the tread rubber and spaced apart in a direction orthogonal to the transport direction.
The elongated member is arranged above the plurality of endless bands, and straddles the plurality of endless bands in a plan view.
The bottom of the elongated member is located between the plurality of first bottoms facing each of the endless bands and the plurality of endless bands in a plan view, and at least not facing any of the plurality of endless bands. With one second bottom,
The method of claim 1, wherein the at least one second bottom has protrusions protruding below the first bottom. The first operation in which the conveyor conveys the tread rubber, and
A second operation after the first operation, in which the first end of the tread rubber is brought into contact with the first receiving surface of the elongated member by the conveyor and then the conveyor is stopped. Including,
The method according to claim 1 or 2, wherein the conveyor speed in the second operation is slower than the conveyor speed in the first operation. The method according to any one of claims 1 to 3, wherein the angle of the first end is 21 degrees or more and 27 degrees or less in a cross section passing through the width direction and the thickness direction of the tread rubber. A conveyor that conveys the mounted tread rubber with the first end in the width direction of the tread rubber at the top.
A long member having a first receiving surface and receiving the first end of the tread rubber conveyed by the conveyor on the first receiving surface so that the center line of the tread rubber is aligned with the first predetermined position. When,
A transport device that transfers the tread rubber in a state where the center line is aligned with the first predetermined position by the long member from the conveyor to the tray by a constant operation.
A system for manufacturing pneumatic tires. The system according to claim 5, wherein at least one of the elongated members has an adjustable position or inclination with respect to the conveyor. The conveyor has a plurality of endless bands extending in the transport direction of the tread rubber and spaced apart in a direction orthogonal to the transport direction.
The elongated member is arranged above the plurality of endless bands, and straddles the plurality of endless bands in a plan view.
The bottom of the elongated member is located between the plurality of first bottoms facing each of the endless bands and the plurality of endless bands in a plan view, and at least not facing any of the plurality of endless bands. With one second bottom,
The system according to claim 5 or 6, wherein the at least one second bottom has protrusions protruding below the first bottom. The conveyor has a first operation of transporting the tread rubber and an operation after the first operation in which the first end of the tread rubber is brought into contact with the first receiving surface of the elongated member. It is configured to perform the second operation of stopping the conveyor.
The system according to any one of claims 5 to 7, wherein the conveyor speed in the second operation is slower than the conveyor speed in the first operation. The system according to any one of claims 5 to 8, wherein the angle of the first end is 21 degrees or more and 27 degrees or less in a cross section passing through the width direction and the thickness direction of the tread rubber.

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