METHOD FOR MANUFACTURING TIRE COMPONENT MEMBER

Abstract

An object of the present invention is to form a tire component member having a desired shape by a ribbon winding method without depending on skill and experience of an operator. Test conditions including the number of windings of winding a ribbon rubber around a forming drum and a feed pitch for moving the ribbon rubber in an axial direction of the forming drum for each rotation of the forming drum are set (Step S11), and a test sample is prepared under the test conditions (Step S12). With respect to the prepared test sample, a width, a cross-sectional area, and a thickness distribution in a width direction are measured (Step S13). Based on these results, the test conditions are corrected to obtain a correction condition (Steps S14 to S19).

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method for manufacturing a tire component member.

Description of the Related Art

Generally, a pneumatic tire is manufactured by bonding a plurality of tire component members such as a tread rubber, a sidewall rubber, a carcass ply, a bead, a bead filler, a belt ply and the like on a forming drum to form a green tire, and then by setting the green tire in a mold for vulcanization molding. As a method for forming such a green tire, a ribbon winding method is known in which a strip-shaped ribbon rubber is wound round an outer peripheral surface of a forming drum while being moved in an axial direction of the forming drum, to form the tire component member such as the tread rubber (for example, see JP-A-2002-254531).

JP-A-2002-254531 discloses a method in which an average circumferential thickness in a circumferential direction of a forming drum of a ribbon rubber formed by win the ribbon rubber is calculated, and winding conditions such as a moving distance (so-called feed pitch) for moving the ribbon rubber in the anal direction of the forming drum for each rotation of the forming drum and the number of windings of winding the ribbon rubber around the forming drum are calculated so that a distribution shape of a total added thickness obtained by total addition of the average circumferential thickness is substantially equal to a cross-sectional shape of the tire component member.

SUMMARY OF THE INVENTION

However, even if the tire component member is formed under forming conditions calculated as in JP-A-2002-254531, the tire component member having a desired shape may not be obtained in some cases. Particularly when the ribbon rubber is wound around the forming drum while extruding the ribbon rubber from an extruder, since the ribbon rubber tends to be deformed, the tire component member having a desired shape may not be obtained from the calculated forming conditions. Therefore, skill and experience by a skilled operator are required in order to determine final forming conditions.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing the tire component member capable of forming the tire component member having a desired shape by the ribbon winding method without depending on skill and experience of the operators.

The method of manufacturing the tire component member the present invention is a method for manufacturing a tire component member by winding a strip-shaped ribbon rubber and an outer peripheral surface of a forming drum while moving the ribbon rubber in an axial direction of the forming drum. The method of manufacturing the tire component member includes: a first step of setting test conditions including the number of windings of winding the ribbon rubber around the forming drum and a feed pitch for moving the ribbon rubber the axial direction of the forming drum for each rotation of the forming drum; a second step of preparing the tire component member under the test conditions set in the first step; a third step of measuring the tire component member prepared in the second step; a fourth step of correcting the test conditions based on measurement results of the third step to obtain a correction condition, and a fifth step of preparing the tire component member under the correction condition obtained in the fourth step.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a configuration of an apparatus for manufacturing a tire component member according to an embodiment;

FIG. 2 is a flowchart showing a process of the apparatus for manufacturing the tire component member in FIG. 1; and

FIG. 3 is a cross-sectional view of the tire component member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

FIG. 1 shows an apparatus 10 (hereinafter also referred to as a manufacturing apparatus) for manufacturing a tire component member according to the present embodiment.

The manufacturing apparatus 10 includes a ribbon rubber supply unit 12, a forming drum 14, a shape sensor 16, and a control device 20. The manufacturing apparatus 10 manufactures a tire component member 50 on the forming drum 14 by a so-called ribbon winding method. In the present embodiment, as the tire component member 50, a case of forming a substantially cylindrical tread rubber which is provided in a tread portion of a pneumatic tire and constitutes a ground contact surface will be described, however, the present invention can also be applied to the manufacture of tire component members such as a sidewall rubber other than the tread rubber.

As shown in FIG. 3, the tire component member 50 includes an inner layer 52 composed of a first inner layer 52A and a second inner layer 52B, and an outer layer 54 composed of a first outer layer 54A and a second outer layer 54B laminated on the outer side of the inner layer 52.

The ribbon rubber supply unit 12 includes an extruder capable of extruding a ribbon rubber 40 into a predetermined cross-sectional shape, and supplies the ribbon rubber to the forming drum while extruding the ribbon rubber from the extruder. A cross-sectional shape of the ribbon rubber 40 is not particularly limited, and various shapes having a flat cross-sectional shape such as a trapezoidal shape, a crescent shape, a triangular shape, or the like can be adopted. A size of the ribbon rubber 40 is not particularly limited, but it can be, for example, 15 to 40 mm in width and 0.5 to 3.0 mm in thickness (thickness in the maximum thickness portion).

The forming drum 14 is configured so that it can rotate about a rotation axis and move in an axial direction (direction parallel to the rotation axis). If the forming drum 14 and the ribbon rubber supply unit 12 are relatively movable in the axial direction, the ribbon rubber supply unit 12 may be configured to be movable in place of the forming drum 14.

The shape sensor 16 is a sensor for measuring an outer shape of the tire component member 50 formed on the forming drum 14, that is, a width, a cross-sectional area, and a thickness distribution in a width direction of the tire component member 50, in a non-contact state on the forming drum 14. The width and the width direction of the tire component member 50 is a direction which coincides with an axial direction of the forming drum 14 and is a direction corresponding to a width direction of the tire when constituting the tire together with other members.

The shape sensor 16 is the sensor for measuring the tire component member 50 in a non-contact state on the forming drum 14. For example, a laser displacement sensor for measuring a distance to a reflection surface by irradiating the tire component member 50 formed on the forming drum 14 with a laser beam can be used as the shape sensor 16. The width, the cross-sectional area, and the thickness distribution in the width direction of the tire component member 50 are measured at a plurality of positions in a circumferential direction of the tire component member 50 at predetermined intervals, and a total value or an average of measurement results at each measurement point can be a measured value of the tire component member.

The control device 20 is constituted by a computer or control microcomputer device including an arithmetic processing unit 21, a memory 34, and a display and is connected to the ribbon rubber supply unit 12, the forming drum 14, and the shape sensor 16. The control device 20 controls an operation of the ribbon rubber supply unit 12, to supply an unvulcanized strip-shaped ribbon rubber 40 from the ribbon rubber supply unit 12 to the forming drum 14 while rotating the forming drum 14, so that the ribbon rubber 40 is wound around the forming drum 14 to form the tire component member 50.

Further, the arithmetic processing unit 21 includes a setting input unit 22, a condition setting unit 24, a drive control unit 26, a data acquisition unit 28, a determination unit 30, and a correction unit 32.

The setting input unit 22 is a unit to be input with various parameters such as the cross-sectional shape of the ribbon rubber 40 supplied from the ribbon rubber supply unit 12 to the forming drum 14, a target shape of a cross-section of the tire component member 50, a winding start position and a winding end position of the ribbon rubber 40, and a movement pattern of the forming drum 14, which are used for calculation of the number of windings R and a feed pitch P to be described later. The input various parameters are temporarily stored in the memory 34.

The condition setting unit 24 calculates the number of windings R of winding the ribbon rubber 40 around the forming drum 14 and a moving distance (the feed pitch) P for moving the ribbon rubber 40 in the axial direction of the forming drum 14 for each rotation of the forming drum based on the various parameters input by the setting input unit 22, and sets the calculated number of windings R and feed pitch P as test conditions. That is, when the number of windings R is N (N: integer, N=41 in FIG. 3) times, feed pitches Pn (n=1, 2, - - - N-1) are set for each turn of the ribbon rubber 40 wound 360 degrees from a winding start end of the ribbon rubber 40. The feed pitch P is set to be smaller than the width of the ribbon rubber 40 and the ribbon rubber 40 is wound so that at least a part thereof overlaps the adjacent ribbon rubbers 40 in the width direction.

The number of windings R and the feed pitch P for each turn obtained by the condition setting unit 24 are input to the drive control unit 26 together with the winding start position and the winding end position of the ribbon rubber 40 and the movement pattern of the forming drum 14. The number of windings R and the feed pitch P for each turn obtained by the condition setting unit 24 are stored in the memory 34.

The drive control unit 26 controls the operation of the ribbon rubber supply unit 12 and the forming drum 14 based on data input from the condition setting unit 24 and the correction unit 32 to prepare the tire component member 50 and its test sample on the forming drum 14.

In the case illustrated in FIG. 3, the ribbon rubber 40 is wound from a winding start end 40A positioned at the center in the width direction of the forming drum 14 to the eighth turn toward one side W1 in the width direction of the tire to form the first inner layer 52A. Further, the ribbon rubber 40 is turned back at an end E1 on one end side of the forming drum 14 and wound from the ninth turn to the center (21th turn) in the width direction of the tire toward the other side W2 in the width direction of the tire to form the first outer layer 54A. Further, the ribbon rubber 40 is continued to be wound to the 28th turn toward the other side W2 in the width direction of the tire to form the second inner layer 52B. Furthermore, the ribbon rubber 40 is turned back at an end E2 on the other side of the forming drum 14 and wound from the 29th turn to the center (41th turn) in the width direction of the tire toward the one side W1 in the width direction of the tire to form the second outer layer 54B. That is, in the case of FIG. 3, the first inner layer 52A is formed by the ribbon rubber 40 from the first to eighth turns, the first outer layer 54A is formed by the ribbon rubber 40 from the ninth to 21th turns, the second inner layer 52B is formed by the ribbon rubber 40 from the 22nd to 28th turns, and the second outer layer 54B is formed by the ribbon rubber 40 from the 29th to 41th turns.

The data acquisition unit 28 receives a displacement signal (a signal indicating a distance from the sensor to the reflection surface) from the shape sensor 16 and acquires data on a shape of the test sample formed on the forming drum 14, specifically data on the width, the cross-sectional area, and the thickness distribution (an outline shape) in the width direction of the test sample. The acquired data is temporarily stored in the memory 34.

The determination unit 30 reads the data on the width, the cross-sectional area, and the thickness distribution in the width direction of the test sample stored in the memory 34 and determines whether the test sample prepared under the test conditions is in the target shape, for example, compares the widths, the cross-sectional areas, and the thickness distributions in the width direction between the test sample prepared under the test conditions and the target shape and determines whether deviation amounts between them are within predetermined ranges.

If the test sample is in the target shape, the determination unit 30 inputs the fact to the correction unit 32. On the other hand, if the test sample prepared under the test conditions is not in the target shape, the determination unit 30 inputs evaluation items, in which the deviation amount from the target shape is out of the predetermined range among the evaluation items of the width, the cross-sectional area, and the thickness distribution in the width direction of the test sample, to the correction unit 32.

The correction unit 32 determines forming conditions of the tire component member 50 to be prepared next based on an input from the determination unit 30, and inputs the forming conditions to the drive control unit 26. A method of determining the forming conditions of the tire component member 50 to be prepared next will be described later.

Next, a process flow according to the present embodiment will be described with reference to FIG. 2.

First, the various parameters such as the cross-sectional shape of the ribbon rubber 40 supplied from the ribbon rubber supply unit 12 to the forming drum 14, and the target shape of the cross-section of the tire component member 50, which are used for calculation of the number of windings R and the feed pitch P, are input to the setting input unit 22 (Step S10).

Next, the condition setting unit 24 calculates the number of windings R and the feed pitch P depending on the target shape based on the various parameters input to the setting input unit 22, and acquires the test conditions (Step S11).

Next, the drive control unit 26 controls the operation of the ribbon rubber supply unit 12 and the forming drum 14 based on the test conditions calculated by the condition setting unit 24, and prepares the test sample of the tire component member 50 on the forming drum 14 (Step S12).

Next, the shape sensor 16 measures the width, the cross-sectional area, and the thickness distribution in the width direction of the test sample of the tire component member 50 prepared on the forming drum 14, and the data acquisition unit 28 acquires the measurement results (Step S13).

Next, the determination unit 30 compares the widths, the cross-sectional areas, and the thickness distributions in the width direction between the test sample prepared under the test conditions and the target shape, and determines whether the deviation amounts between them are within the predetermined ranges (Steps S14 to S16).

Specifically, when the deviation amount of the width between the test sample and the target shape exceeds the predetermined range (No in Step S14), the correction unit 32 adjusts at least one of the number of windings R (in FIG. 3, a total of 15 times of the first to eighth turns and the 22nd to 28th turns) of the ribbon rubber 40 forming the innermost layer, that is, the inner layer 52, and the feed pitch P (in FIG. 3, P1 to P7 and P21 to P27) to determine a correction condition (Step S17). As a method for determining the correction condition in this case, for example, when the width of the test sample is shorter than the width of the target shape, the feed pitch P of all the ribbon rubbers 40 constituting the inner layer 52 increased by a distance obtained by proportionally dividing an insufficient length (width) by the number of windings of the ribbon rubber 40 constituting the inner layer 52, or the number of windings R increased to compensate for the insufficient length. Further, when the width of the test sample is longer than the width of the target shape, the feed pitch P of all the ribbon rubbers 40 constituting the inner layer 52 is decreased by a distance obtained by proportionally dividing an exceeding length (width) by the number of windings of the ribbon rubber 40 constituting the inner layer 52, or the number of windings R is decreased to shorten the exceeding length.

When the deviation amount of the width between the test sample and the target shape is within the predetermined range but the deviation amount of the cross-sectional area exceeds the predetermined range (No in Step S15), the correction unit 32 adjusts the number of windings (in FIG. 3, a total of 26 times of the ninth to 21st turns and the 29th to 41st turns) R of the outermost layer, that is, the outer layer 54 to determine the correction condition (Step S18). As a method of determine the correction condition in this case, the cross-sectional area of the ribbon rubber 40 is calculated from the measured value of the cross-sectional area of the test sample and the number of windings R when the test sample is prepared, so that the number of windings R is adjusted by the number of windings corresponding to insufficient area or an exceeding area based on the calculated cross-sectional area.

Further, when the deviation amounts of the width and cross-sectional area between the test sample and the target shape are within the predetermined ranges, but the thickness distribution in the width direction exceeds the predetermined range (No in Step S16), the correction unit 32 adjusts the feed pitch P (in FIG. 3, P8 to P20 and P28 to P40) of the outermost layer, that is, the outer layer 54 to determine the correction condition (Step S19). As a method of determining the correction condition in this case, the feed pitch P of the ribbon rubber 40 at the position in which the thickness is insufficient is reduced, and the feed pitch P of the ribbon rubber 40 at the position in which the thickness is excessive is increased. An amount of change in the feed pitch P can be changed depending on a deviation of the thickness between the test sample and the target shape.

When the correction unit 32 determines the correction condition in Step S17 to S19, the process returns to Step S12 again, and the drive control unit 26 controls the operation of the ribbon rubber supply unit 12 and the forming drum 14 based on the correction condition calculated by the correction unit 32 to prepare a second test sample of the tire component member 50 on the forming drum 14.

Thereafter, preparation (Step S12), measurement (Step S13), evaluation (Steps S14 to S16) of the test sample, and determination of the correction condition (Steps S17 to S19) are repeated until the deviation amounts of all the evaluation items of the width, the cross-sectional area, and the thickness distribution in the width direction between the test sample end the target shape fall within the predetermined ranges. When the deviation amounts of the evaluation items between the test sample and the target shape are within the predetermined ranges (Yes in Step S16), the correcting unit 32 determines that the prepared test sample is in the target shape, and sets an initial condition or the correction condition in the forming conditions without modification, so that the tire component member 50 is manufactured under this condition.

According to the present embodiment, it is possible to obtain the tire component member 50 by winding the ribbon rubber around the outer peripheral surface of the forming drum while moving the ribbon rubber in the axial direction of the forming drum without requiring skill and experience by a skilled operator.

Further, in the present embodiment, since the width, the cross-sectional area, and the thickness distribution in the width direction of the test sample of the tire component member 50 formed on the forming drum 14 are measured in a non-contact state, it is possible to accurately measure the test sample without deformation during the measurement.

The above embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms and various omissions, substitutions, and changes can be made without departing from the gist of the invention.

For example, in the present embodiment, a description is given of a case where the ribbon rubber 40 is directly wound around the outer peripheral surface of the forming drum 14 to prepare the test sample of the tire component member 50. However, for example, the test sample of the tire component member 50 may be provided on another tire component member already provided on the outer peripheral surface of the forming drum 14. In this case, the share of the outer peripheral surface of the forming drum 14 is measured before preparing the test sample of the tire component member 50, and a difference between the measurement result after the test sample is prepared and the measurement result before the test sample is prepared may be used as a measured value.

In the present embodiment, the number of windings R and the feed pitch P calculated by the condition setting unit 24 based on the various parameters input by the setting input unit 22 are set as the test conditions, however, conditions directly input by the operator may be set as the test conditions, or previously used conditions may be set as the test conditions.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

10: manufacturing apparatus, 12: ribbon rubber sun unit, 14: forming drum, 16: shape sensor, 20: control device, 21: arithmetic processing unit, 22: setting input unit, 24: condition setting unit, 26: drive control unite, 28: data acquisition unit, 30: determination unit, 32: correction unit, 34: memory, 35: display, 40: ribbon rubber, 50: tire component member, 52: inner layer, 52A: first inner layer, 52B: second inner layer, 54: outer layer, 54A: first outer layer, 54B: second outer layer.

Claims

1. A method for manufacturing at tire component member by winding a strip-shaped ribbon rubber around an outer peripheral surface of a forming drum while moving the ribbon rubber in an axial direction of the forming drum, comprising: a first step of setting test conditions including the number of windings of winding the ribbon rubber around the forming drum and a feed pitch for moving the ribbon rubber in the axial direction of the forming drum for each rotation of the forming drum;a second step of preparing the tire component member under the test conditions set in the first step;a third step of measuring the tire component member prepared in the second step;a fourth step of correcting the test conditions based on measurement results of the third step to obtain a correction condition; anda fifth step of preparing the tire component member under the correction condition obtained in the fourth step.

2. The method for manufacturing the tire component member according to claim 1, wherein in the third step, a width, a cross-sectional area, and a thickness distribution in a width direction of the tire component member prepared in the second step are measured, andin the fourth step, the test conditions are corrected based on the width, the cross-sectional area, and the thickness distribution in the width direction of the tire component member measured in the third step to obtain the correction condition.

3. The method for manufacturing the tire component member according to claim 2, wherein the second step includes a step of preparing the tire component member by laminating a plurality of layers formed by winding the ribbon rubber around the outer peripheral surface of the forming drum while moving the ribbon rubber in the axial direction of the forming drum, andwhen the width of the tire component member measured in the third step does not satisfy a predetermined condition, at least one of the feed pitch and the number of windings of a layer arranged in the innermost layer is adjusted to obtain the correction condition in the fourth step.

4. The method for manufacturing the tire component member according to claim 2, wherein the second step includes a step of preparing the tire component member by laminating a plurality of layers formed by winding the ribbon rubber around the outer peripheral surface of the forming drum while moving the ribbon rubber in the axial direction of the forming drum, andwhen the cross-sectional area of the tire component member measured in the third step does not satisfy a predetermined condition, the number windings of a layer arranged in the outermost layer is adjusted to obtain the correction condition in the fourth step.

5. The method for manufacturing the tire component member according to claim 2, wherein the second step includes a step of preparing the tire component member by laminating a plurality of layers formed by winding the ribbon rubber around the outer peripheral surface of the forming drum while moving the ribbon rubber in the axial direction of the forming drum, andwhen the thickness distribution in the width direction of the tire component member measured in the third step does not satisfy a predetermined condition, the feed pitch of a layer arranged in the outermost layer is adjusted to obtain the correction condition in the fourth step.

6. The method for manufacturing the tire component member according to claim 1, wherein a width, a cross-sectional area, and a thickness distribution in a width direction of the tire component member prepared in the second step are measured in a non-contact state on the forming drum in the third step.

7. The method for manufacturing the tire component member according to claim 2, wherein the width, the cross-sectional area, and the thickness distribution in the width direction of the tire component member prepared in the second step are measured in a non-contact state on the forming drum in the third step.