JP2003053856A - Tire manufacturing method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a tire excellent in uniformity by improving RFV or the like. SOLUTION: In the tire manufacturing method, a long continuous tread strip material extruded from an extruder is cut in lengths to form a tread section and this tread section is preserved in such a state that the shrinkage of both end parts of the tread section with the elapse of time is forcibly suppressed before sent to a molding process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire manufacturing method and apparatus thereof, and more particularly to a manufacturing method for improving the FV level of a tire by suppressing temporal shrinkage during tread storage before a molding process. Manufacturing equipment

[0002]

2. Description of the Related Art In recent years, as performance of tires, demands for FV such as RFV have been severely demanded. In general, a tire manufacturing process is a “mixing process” in which various raw materials are mixed, and these materials are extruded from an extruder or the like and cut into predetermined lengths to obtain treads, carcasses, beads, belts, etc. "Member processing process" for manufacturing each component, "molding process" for assembling each of these components into one tire shape, and "vulcanization" for heating / pressurizing the assembled green tire (green tire) The process such as “process” is provided.

In the above molding process, in order to make each of the strip-shaped components into an annular shape, a joint portion is formed in which both ends thereof are overlapped with each other. One of the factors causing the non-uniformity of the tire is that the tire rigidity and dimensions change in the tread joint.

In the above molding process, a method of dispersing the joints of the respective components at optimal positions has been proposed. However, in the conventional manufacturing method, for example, one strip of a regular length is used. If the tread itself has non-uniform dimensions, there is a limit to improving the uniformity of manufactured tires such as RFV.

Specifically, in the member processing step, a tread is provided by installing a shrinkage roller, a dancer roller or the like in an extrusion line that conveys a tread strip continuously extruded from an extruder. In the extrusion line, try not to stretch the strip (rubber) as much as possible,
A method has been adopted in which the amount of shrinkage is suppressed, or all the shrinkage is completed in the extrusion line by utilizing the rubber property, so that the subsequent shrinkage is eliminated.

[0006]

Conventionally, as described above, the tread (standard length material) after cutting by the measures in the extrusion line.
Even if we tried to eliminate the shrinkage, the actual production line could not completely eliminate the shrinkage because the extrusion line was about 10 to 15 minutes.

That is, even if the shrinkage is suppressed in the extrusion line, both ends of the tread (standard length material) shrink more than the middle portion in the longitudinal direction during storage after cutting and before the molding process. Cause deformation.

Therefore, in the conventional tire manufacturing method, the tire manufactured through the subsequent molding step and vulcanization step is
At the tread joint, the rigidity and the size of the tread joint were changed to a large extent, and there was a limit to the improvement of RFV.

The present invention is a conventional tire manufacturing method (apparatus).
It is an object of the present invention to provide a method (apparatus) for solving the above-mentioned problems in (1) to eliminate the unevenness in the tread joint and to easily manufacture a tire having a small FV and excellent uniformity. .

[0010]

In order to achieve the above-mentioned object, a method of manufacturing a tire according to the present invention comprises cutting a long continuous tread strip extruded from an extruder into a predetermined length. This is a method of producing a tread standard material, then storing the tread standard material in a state in which both end portions of the tread standard material are forcibly suppressed from shrinking with time, and then sending the tread standard material to a molding step.

Further, in order to forcibly suppress the time-dependent shrinkage of both end portions of the tread standard length material, a sheet body having little expansion and contraction at room temperature is attached to each of the both end portions. Also, cut the tread strip to a predetermined length to make a tread standard length material,
On the conveying path for conveying the tread standard material, both ends in the length direction of the tread standard material are detected by a detector, and a sheet body having little expansion and contraction at room temperature is attached to each of the both ends. Then
This is a method of forcibly suppressing the time-dependent contraction of the both ends.

Alternatively, it is picked up from the conveying path for conveying the tread standard material and placed on the leaf tray, and the leaf trays on which the tread standard material is placed are sequentially stacked, and at the same time, on the lower leaf tray. In this method, both ends of the tread standard length material are pressed against the back surface of the upper leaf tray to forcibly suppress the time-dependent shrinkage of the both ends and store the tread standard length material.

The tire manufacturing apparatus according to the present invention is
Long continuous tread strip extruded from the extruder, on the conveying path of the tread constant length material made by cutting into a predetermined length, the lengthwise ends of the tread constant length material are sequentially A detector for detecting and a sheet body sticking device for sequentially sticking a sheet body with little expansion and contraction at room temperature to each of the both end portions in accordance with a detection signal from the detector, are provided with both end shrinkage suppressing means, and molded. Before the step, the tread standard length material is configured to be stored in a state in which the temporal contraction of the both end portions is forcibly suppressed.

The tread strip material extruded from the extruder is cut into a predetermined length, and a tread constant length material is conveyed between the conveying path and the molding machine for the next step. In a tire manufacturing apparatus equipped with a storage device having a plurality of leaf trays that can be stacked in a plurality of upper and lower stages for temporarily storing standard length materials, a lower leaf is provided on the back side of the upper leaf tray of the storage device. A pressing portion is formed by pressing both end portions in the longitudinal direction of the tread standard length material placed on the tray to forcibly suppress shrinkage over time.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the illustrated embodiments. 1 and 2 (outside left drawing)
The long continuous tread strip extruded from the extruder is cut into a predetermined length by a cutter device (not shown), and is used as a tread constant length material T as a conveyor path U such as a conveyor.
It is sequentially conveyed as indicated by arrow A above.

Reference numeral 1 is a detector for sequentially detecting both end portions 2 and 2 in the length direction of the tread constant length material T conveyed in this way, and an optical sensor, a contact type sensor or the like is used, It is arranged close to the transport path U. Then, the detection signal B from the detector 1 is sent to the control circuit 3.

A sheet body sticking device C for sticking the sheet body 4 to the both ends 2 of the tread length measuring material T one after another is arranged on the conveying path U. As the sheet body 4,
A material that does not expand or contract at room temperature--for example, polypropylene--and one side that is slightly larger than the width dimension W of the tread standard length material T and the end portion 2 are overlapped at least 40 mm or more from the extreme end. As described above, a rectangular thin plate piece (sheet piece) having the other side of 40 mm or more is used.

Each time the sheet sticking apparatus C receives the detection signal B from the detector 1, it operates by the output signal B'transmitted from the control circuit 3 and the longitudinal (feeding) direction of the end 2 is obtained. The sheet body 4 is attached to the correct position of. For example, the feed speed of the transport path U is input to the control circuit 3 in advance, and the pressing operation timing of the pressing roller 6 (described later) is delayed by a predetermined calculation time from the time when the signal B is received from the detector 1. In this way, the end portion 2 is pressed by the pressing roller 6.
The sheet body 4 is pressed and adhered to the accurate predetermined position of.

In the illustrated example, the pressing roller 6 is rotatably attached to the tip of the swing arm 7 by a shaft 8 and the swing arm 7 is moved by a reciprocating actuator 9 as shown by arrow E. Swing up and down.

According to the output signal B'from the control circuit 3,
By actuating the actuator 9, the pressing roller 6 is pressed against the end portion 2 of the tread standard length material T (which is sequentially fed), and the sheet body 4 which is once attached to the peripheral surface of the roller 6 in advance. Is attached to the end 2. In order to attach the sheet body 4 to the peripheral surface of the pressing roller 6 in advance, another rolling roller (not shown) and a feed belt for the sheet body 4 ... Or a suction cup (for the sheet body 4 ... ) Holding the reciprocating sticking operation plate to the pressing roller 6 to the sheet body 4 ...
Can be attached.

In FIG. 1 and FIG. 2 described above, the detector 1, the control circuit 3, and the sheet sticking device C constitute the both end contraction suppressing means G. By this contraction suppressing means G,
While the tread standard length material T is subsequently taken out of the transport path U and temporarily stored, before the molding step ───
The both ends 2, 2 are forcibly suppressed from contracting with time.

To explain further, the transport path U such as a conveyor
From the above, the tread standard length material T with the sheet bodies 4 and 4 is picked up automatically by a robot or the like or manually, and stored in a leaf tray-shaped storage or other storage location.
Although stored, both end portions 2 and 2 (contracted more than the middle portion in the longitudinal direction in the past) are surely suppressed by the sheet members 4 and 4 from contracting with time.

The embodiment of the tire manufacturing apparatus according to the present invention has been described above. The manufacturing method using such an apparatus will be described below.
That is, a continuous long tread strip extruded is cut into a predetermined length by a cutter to make a tread constant length material T, and a tread constant length material is conveyed on a conveying path U for conveying the tread constant length material T. Both ends 2 and 2 in the length direction of T are detected by the detector 1,
Sheets 4 and 4 that are less stretchable at room temperature
It is a method of sticking to each of the two and forcibly suppressing the temporal contraction (during storage) of the both end portions 2 and 2.

It should be noted that in order to forcibly suppress the time-dependent shrinkage of both ends 2, 2 of the tread length measuring material T, a sheet body having little expansion and contraction at room temperature may be attached to both ends 2, 2. For example, a device other than those shown in FIGS. 1 and 2 can be freely used. For example, a sheet body sticking plate that can be approached and separated from the transport path U in the vertical direction is a detector attached to the sticking plate itself or in the vicinity thereof. While detecting the end portion 2 of the tread constant length material T, the sheet body 4 may be attached, and in some cases, the sheet body 4 may be manually attached to the end portions 2 and 2. May be. In addition (in summary) Tread standard length material T
Is a method of manufacturing a tire in which both end portions 2 and 2 of the tire are forcibly restrained from being shrunk with time and stored, and then sent to a subsequent molding step.

FIG. 3 is a perspective view showing another embodiment of the tire manufacturing apparatus of the present invention, which is a tread obtained by cutting a long continuous tread strip extruded from an extruder into a predetermined length. A storage device having a plurality of leaf trays 10 which can be stacked in a plurality of upper and lower stages for temporarily storing the tread constant-size material T between a conveying path for conveying the constant-size material T and a molding machine as a next step. F is shown.

This storage device F is provided with an upper leaf tray 10
On the back surface 11 of the tread, there are formed pressing portions 12, 12 for pressing the longitudinal end portions 2, 2 of the tread standard length material T placed on the lower leaf tray 10 to forcibly suppress the shrinkage over time. . Figure 3
In the concrete example of the above, a plurality of upper and lower leaf trays 10 each having a rectangular plate shape are used.
... indicates that each leaf tray 10 is opened and closed by swinging its front edge up and down at its rear edge side at predetermined vertical intervals and with the uppermost leaf tray 10 slightly open upward. Freely and pivotally supported. Then, the tread standard length material T is placed on the leaf tray 10 in the left-right direction in order from the lower one to the upper one.
On the back surface of 10, the pressing parts 12, 12 made of a rectangular piece of sponge such as polyurethane foam are attached along the left and right edges of each leaf tray 10, and the tread on one leaf tray 10 is fixed. The scale material T is pressed by the pressing portions 12, 12 of the leaf tray 10 one above it, and the contraction over time can be forcibly suppressed.

In other words, while picking up from the transport path U for transporting the tread constant-size material T and mounting it on the leaf tray 10, the leaf trays 10 on which the tread standard-size material T is mounted are sequentially stacked. , The lower leaf tray
Both ends 2, 2 of the tread standard length material T on 10 are pressed by the back surface of the upper leaf tray 10 to forcibly suppress shrinkage of both ends 2, 2 for storage.

It should be noted that, in FIGS. 1 and 2 and FIG. 3, the region for pressing both end portions 2, 2 is preferably 40 mm or more from the outermost end portion. The reason is that the 40 mm range tends to cause shrinkage over time, which must be suppressed.
The tire manufactured according to the present invention is a pneumatic tire and is mainly a radial tire.

Next, by the storage device F illustrated in FIG.
The tread standard length material T was pressed at both end portions 2 and 2 in the area of 50 mm, respectively, and it was compared with the one after 6 hours (test product) and the conventional non-suppressed storage (conventional product). The actual measurement results are shown in Table 1 below.

[0030]

[Table 1]

Then, the test product of Table 1 and the conventional product are
Then, it was molded and vulcanized to manufacture a tire (finished product). The tire size is 275 / 70R16. The measured values of RFV (radial force variation) of this tire are shown in Table 2 below.

[0032]

[Table 2]

From the above Tables 1 and 2, according to the manufacturing method (apparatus) of the present invention, the difference in the tread gauge can be remarkably reduced, the tire RFV can be improved, and the tire uniformity can be greatly improved. You can see that it works.

[0034]

According to the present invention, with the above-mentioned structure, the FV such as RFV can be remarkably improved and the uniformity of the tire can be surely improved. It can be implemented inexpensively (according to claim 2), and
A large number of tread length materials T ... Can be easily stored. (According to the third or fifth aspect), the sheet body can be efficiently attached on the conveying path for efficiently suppressing the shrinkage. In addition, the sheet body can be attached to the correct position. By using the leaf tray effectively (according to claim 4 or 6), the compulsory suppression of contraction can be realized.

[Brief description of drawings]

FIG. 1 is a front view showing the main part of an embodiment of the present invention.

FIG. 2 is a plan view of a main part.

FIG. 3 is a perspective view showing another embodiment.

[Explanation of symbols]

1 detector 2 ends 4 sheet body 10 leaf tray 11 Back side 12 Pressing part B detection signal C sheet attachment device F storage device G Both ends contraction suppressing means T-tread standard length material U transport path

Claims (6)

[Claims] 1. A long continuous tread strip extruded from an extruder is cut into a predetermined length to prepare a tread standard material, and then both ends of the tread standard material shrink with time. To
A method for manufacturing a tire, characterized in that the tire is stored in a suppressed state and then sent to a molding step. 2. The tire manufacturing method according to claim 1, wherein a sheet body having little expansion and contraction at room temperature is attached to each of the both end portions of the tread standard length member in order to forcibly suppress the time-dependent shrinkage of the both end portions. Method. 3. A tread standard length material is produced by cutting a tread strip into a predetermined length, and both ends of the tread constant length material in the length direction are conveyed on a conveying path for conveying the tread standard length material. 2. The tire manufacturing method according to claim 1, wherein the sheet is detected with a detector, and a sheet body having little expansion and contraction at room temperature is attached to each of the both end portions to forcibly suppress the temporal contraction of the both end portions. Method. 4. The tread constant-size material is picked up from a conveying path and placed on a leaf tray, and the leaf trays on which the tread standard-size material is placed are sequentially stacked, and at the same time, on the lower leaf tray. 2. The tire manufacturing method according to claim 1, wherein both ends of the tread standard length material are pressed against the back surface of the upper leaf tray to forcibly suppress temporal contraction of the both ends and stored. 5. A lengthwise direction of the tread constant length material is provided on a conveying path for conveying the tread constant length material made by cutting a long continuous tread strip extruded from an extruder into a predetermined length. Both ends shrinkage suppressing means comprising a detector for sequentially detecting both ends of the sheet, and a sheet sticking device for sequentially sticking a sheet body with little expansion and contraction at room temperature to each of the ends according to a detection signal from the detector. The tire manufacturing apparatus is configured so as to be provided and stored in a state in which the temporal shrinkage of the both ends of the tread standard length material is forcibly suppressed before the molding step. 6. The tread, which is a continuous continuous tread strip extruded from the extruder, is conveyed between a conveying path for conveying the tread constant length material cut into a predetermined length and a molding machine for the next step. In a tire manufacturing apparatus equipped with a storage device having a plurality of leaf trays that can be stacked in a plurality of upper and lower stages for temporarily storing standard length materials, a lower leaf is provided on the back side of the upper leaf tray of the storage device. A tire manufacturing apparatus, comprising: a pressing portion that presses both longitudinal end portions of a tread standard length material placed on a tray to forcibly suppress shrinkage over time.