JP2005238799A - Device and method for molding rubber strip material for tire production and method for producing tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for molding a rubber strip material which is capable of molding a thinner and wider rubber strip material without decreasing an extrusion speed and further capable of shortening a molding cycle time, resulting in an increase in tire production efficiency. <P>SOLUTION: In a method for molding a rubber strip material 1, when a rubber material is continuously extruded to mold into ribbon shaped product, controlled temperatures in a body case 11 of an extruder 10, a screw axis 12 in its inner part and a head part 13 containing a dice 15 are adjusted to be differentiated from one another in such a way that the controlled temperature of the body case 11 is set higher than that of the screw axis 12, and the controlled temperature of the head part 13 is set higher than that of the body case 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for molding a rubber strip material used for manufacturing a tire composed of a plurality of tire rubber members, and a method for manufacturing a tire using a rubber strip material molded by this method. .

   Generally, a tire is composed of a plurality of tire rubber members. Typically, as shown in FIG. 15, the inner liner rubber portion 2, the tread rubber portion 3, the sidewall rubber portion 4, and the rim strip rubber portion 5 are used. Etc. are formed of rubber members according to the required characteristics. In order to mold the rubber member constituting each of these parts, the target rubber is formed by continuously extruding from an extruder through a die corresponding to the cross-sectional shape of each rubber member, and then cutting to a fixed size. I got the parts. In the molding of a tire, the rubber member is sequentially pasted on a rotating support such as a molding drum.

  However, in recent years, the accuracy requirements for the tire shape have become stricter, and the following Patent Document 1 and Patent Document 2 describe the problem of distortion and shrinkage of a member by continuously extruding it with an extruder and cutting it to a fixed size. As disclosed, an unvulcanized rubber strip material extruded in a ribbon shape is wound on a rotating support such as a molding drum in a spiral manner along the circumferential direction of the tire. A rubber member having a cross-sectional shape is formed.

  Even in the present applicant, when molding a rubber member using the ribbon-shaped rubber strip material, if the winding start position and the end position of the rubber strip material are greatly deviated in the tire circumferential direction, Since the uniformity is impaired and the tire running performance is adversely affected, the positional deviation between the winding start position and the winding end position of the rubber strip material is in the range of 0 to 5 mm in the tire circumferential direction. It proposes improving the weight balance and the like (Patent Document 3).

  In addition, if the amount of overlap in the width direction of the rubber strip material is too large, the unevenness in the cross-sectional shape of the molded rubber member may increase, and the target cross-sectional shape may not be achieved. Therefore, it is also proposed to wrap and mold the rubber strip material so that the overlap amount in the tire width direction is 1/2 to 1/5 of the width dimension of the rubber strip material. (Patent Document 4).

  In the above molding, in order to eliminate irregularities and steps when a part of the rubber strip material is overlapped and wound, the cross-sectional shape of the rubber strip material is a substantially crescent shape in which the thickness is reduced on both sides of the width to be overlapped. The cross-sectional shape is substantially triangular or trapezoidal.

  As shown in FIG. 16, this rubber strip material has a shape of the discharge port 117 at the tip of the inner hole portion 115a of the molding die 115 provided in the head portion 113 of the extruder 110, for example, a flat substantially crescent shape or substantially the same. In a triangular shape, the rubber material flowing from the head portion 113 into the inner hole portion 115a of the die 115 is extruded from the discharge port 117 and molded.

  As shown in FIGS. 17 to 19, the forming die 115 used for this forming is provided with a drawing step surface 118 at the front end portion of the inner hole portion 115 a, and the central portion of the step surface 118. A discharge port 115 a is provided, and the inner hole portion 115 a generally has a taper shape that becomes gradually narrower from the rear end opening 119 connected to the head portion 113 toward the throttle step surface 118. The pressure of the rubber material fed into the die 115 is increased by the squeezing effect of the squeezing step surface 118, and the rubber material is pushed out from the discharge port 117.

  By the way, in the rubber strip material formed as described above, it is preferable that the thickness of both sides of the rubber strip is thin, and it is preferable to wrap and mold a part of the rubber strip material. As a result, a larger flow velocity difference or pressure difference occurs at the portion, and as a result, the thinner the thickness at the both sides of the width, the more easily the cracks, chips, etc. are lost at the ears at the ends of the width.

  In particular, in the molding methods disclosed in Patent Document 3 and Patent Document 4, the width is 5 to 30 mm, the thickness of the width center portion is 0.5 to 3.0 mm, and the thicknesses at both ends of the width are 0.05 to 0.2 mm. However, in such a case, in order to form the thickness of the width side ends to 0.05 to 0.2 mm, an extruder is used. It is necessary to slow down the extrusion speed from the die and make it thin by applying tension to the extruded rubber strip material.Therefore, cracks and cracks are missing at the ears on both sides of the thin width. It tends to occur.

  Further, in the manufacture of tires, the molding cycle time for each tire is a very important factor. However, because of the shape of the inner hole portion of the conventional die, the central portion and both sides of the die inner hole portion are formed. The difference in the flow velocity of the rubber material at the section is large, so if the width of the rubber strip material is large, it is difficult to obtain the desired thickness at both ends of the width, and if the width is narrow, the thickness at both ends of the width is also thick. Therefore, in order to satisfy the condition of increasing the width and reducing the thickness at both ends of the width, rather than molding at a lower extrusion speed, the cycle time of molding in tire manufacturing is therefore reduced. There was nothing else.

Most of the above problems are caused by the difference in physical properties of the rubber strip material extruded from the extruder as a viscoelastic body and the difference in the flow velocity of the rubber material in the die inner hole. In the use of the strip material, it is desired to solve the above problems. In particular, the conditions for reducing the thickness (0.05 to 0.2 mm) at both ends in the width direction can greatly contribute to shortening the vulcanization time of the tire, and bear and air entering the tire surface after vulcanization of the tire. Therefore, it is strongly desired to solve the above problem.
JP 2000-202921 A JP-A-9-29858 JP 2002-178415 A JP 2002-205512 A

  The present invention has been made in view of the above, and it is possible to extrude a wider and thin rubber strip material without any problem without lowering the extrusion speed from the die in the extruder. Provided is a rubber strip material molding method and apparatus capable of suppressing an increase in molding cycle time, and further a tire manufacturing method for molding a rubber member using the rubber strip material thus molded. It is to provide.

  One aspect of the present invention for solving the above problems is that the rubber used in a tire manufacturing process in which a rubber member for a tire is formed by spirally winding an unvulcanized rubber strip material extruded from a molding die of an extruder. A method for forming a strip material, wherein the temperature of the main body case is controlled from the screw shaft by differentiating the temperature control temperature of each portion of the head portion including the main body case of the extruder, the internal screw shaft and the die. The rubber material is continuously extruded in a ribbon shape by setting the temperature to be higher and the temperature control temperature of the head portion higher than that of the main body case.

  By extruding in this way, it is possible to greatly reduce the occurrence of cracks, cracks, and the like at both ends of the width without slowing the extrusion speed as in the prior art. As a result, a wide and thin rubber strip material can be continuously formed without fear of being lost without reducing the extrusion speed.

  In the above, the temperature adjustment temperature of the die is set to be equal to or higher than the temperature adjustment temperature of the head portion, and extrusion molding is performed. Thereby, the extrusion molding of the rubber strip material can be performed more satisfactorily.

  In the molding method described above, the rubber strip material extruded by the molding die has a cross-sectional shape in which the thickness is gradually reduced from the width center portion toward the width sides, the width is 5 to 50 mm, and the thickness of the width center portion is 0. It can be extruded into a ribbon shape having a thickness of 0.5 to 3.0 mm and a thickness at both side ends of 0.05 to 0.2 mm. With such a shape, a rubber member having a desired cross-sectional shape can be molded accurately and smoothly by being wound in a spiral shape, and the vulcanization time of the tire can be shortened, and further, the bearing generated on the tire surface can be reduced. In addition, it can contribute to the prevention of defects such as air entering.

  Another aspect of the present invention is a molding apparatus used in the molding method of the rubber strip material, wherein the temperature of each part of the head portion including the main body case of the extruder, the internal screw shaft, and the dice. The temperature difference of the main body case is set higher than that of the screw shaft, and the temperature adjustment temperature of the head portion is set higher than that of the main body case. In this case, it is preferable that the temperature control temperature of the die is set to be equal to or higher than the temperature control temperature of the head portion. By using such a molding apparatus, the above-described method for molding a rubber strip material can be suitably implemented.

  In the rubber strip molding apparatus, the molding die is provided with a molding discharge port continuous at the front end portion of the inner hole portion thereof via the drawing step surface, and a rear end connected to the head portion. In the middle of the flow direction of the inner hole portion extending from the opening to the discharge port, an intermediate throttle portion is provided to provide a step difference between the rear end side inner hole portion and the front end side inner hole portion, with respect to the rubber material. What is comprised so that a diaphragm may be given by the said intermediate | middle aperture | diaphragm | squeeze part and the cross section for an aperture | diaphragm | squeeze part is preferable.

  By using the die having such a shape, the rubber material fed into the die can be given a two-stage drawing action at the intermediate drawing portion and the drawing section at the tip portion. The flow rate difference and pressure fluctuation at the stepped step surface inside the discharge port become smaller than before, and the rubber strip material can be extruded from the discharge port with a substantially uniform pressure. Therefore, it is possible to further enhance the effect of preventing the lack of the ears on both sides of the width, and the rubber strip material molding method can be more satisfactorily implemented. In particular, it is possible to significantly increase the limit speed at which the ear part is lost compared to a conventional die, increase the extrusion speed, and make the rubber strip material wider and thinner at both ends than before. It can be molded. In the case where the front end side inner hole portion has a long hole shape corresponding to the longitudinal direction of the molding discharge port as viewed from the rear end side and is continuous with the stepped surface of the front end portion, Differences in flow velocity and pressure fluctuations at the stepped portion are less likely to occur, and the effect of preventing missing ears can be further enhanced.

  Still another aspect of the present invention is a tire manufacturing method comprising a plurality of tire rubber members, wherein at least one of the rubber members is not extruded from a die of an extruder by the molding method of the invention. A rubber member for a tire having a predetermined shape is formed by supplying a rubber strip material for vulcanization onto a rotating support for forming a tire and winding a part of the rubber strip in a spiral manner in the circumferential direction of the tire. And As a result, the rubber member can be molded using the wide and thin rubber strip material as described above, and the tire can be efficiently manufactured without reducing the molding cycle time. In addition, a tire rubber member having a desired cross-sectional shape can be molded with high accuracy, and therefore, the vulcanization time of the tire can be shortened, and further, the occurrence of defects such as air entry on the tire surface can be prevented, and both quality tires can be manufactured.

  In the tire manufacturing method, it is preferable that the rubber strip material is molded so that the positional deviation between the winding start position and the winding end position is in the range of 0 to 5 mm in the tire circumferential direction. As a result, the weight variation of the rubber member can be reduced, and a tire with improved weight balance and uniformity can be manufactured.

  Further, it is preferable to wind the rubber strip material so that the overlapping amount in the tire width direction is 1/2 to 1/5 of the width dimension of the rubber strip material.

  If the amount of overlap is greater than ½, the unevenness of the overlapped portion becomes conspicuous, making it difficult to obtain a desired cross-sectional shape. By making the overlap amount smaller than 1/2, it becomes easy to obtain a smooth cross-sectional shape. Further, when the overlap amount is smaller than 1/5, the rubber strip is easily separated. Therefore, it is preferable to set the overlap amount to ½ to １ ／ as described above, whereby a tire with improved weight balance and uniformity can be obtained.

  Further, at least two rubber members of the plurality of tire rubber members are molded by spirally winding the corresponding rubber strip material in the tire circumferential direction in each winding step, and each rubber strip is formed. It is preferable that the winding start position of each material is shifted in the tire circumferential direction, and the phase shift is set to 10 degrees or more to perform winding molding.

  That is, when the winding start positions of the plurality of rubber members are the same positions as seen from the tire circumferential direction, the weight balance and the like may be lost. Therefore, as described above, the winding start position has a phase shift of 10 degrees or more. Thereby, tire performance, such as a desired weight balance, can be maintained.

  As described above, according to the molding method and apparatus of the rubber strip material of the present invention, the temperature adjustment temperature of each part of the main body case, the screw shaft, and the head portion of the extruder is adjusted from the screw shaft. By setting the temperature to be higher and the temperature control temperature of the head part higher than that of the main body case, it is possible to prevent defects such as missing in the ears at both ends without reducing the extrusion speed from the molding die. The generation can be greatly reduced or suppressed, rubber strips that are wider and thinner on both sides can be efficiently extruded, and the molding cycle time for each tire can be reduced, resulting in efficient tires. Can be manufactured.

  Further, according to the tire manufacturing method of the present invention using the rubber strip material, the tire can be efficiently manufactured without reducing the molding cycle time, and the tire rubber member having a desired cross-sectional shape can be accurately produced. High quality tires with improved weight balance and uniformity can be efficiently manufactured.

  Next, embodiments of the present invention will be described based on examples shown in the drawings.

  FIG. 1 is a schematic side view of an extruder constituting a molding apparatus used in the method for molding a rubber strip material of the present invention, FIG. 2 is a sectional view of the extruder, and FIG. 3 illustrates the shape of a discharge port of a die. FIG. 4 is a front view from the rear end side of the die, and FIGS. 5 and 6 are cross-sectional views of the die.

  In the present invention, the rubber strip material 1 to be molded includes a tire (radial tire) T shown in FIG. 15, that is, a plurality of inner liner rubber portions 2, tread rubber portions 3, sidewall rubber portions 4, rim strip rubber portions 5, and the like. In the manufacturing process of the tire T composed of the tire rubber member, at least one of the plurality of rubber members, for example, a rubber member such as the inner liner rubber portion 2 or the tread rubber portion 3 is wound and molded. It is used for, and forms a ribbon.

  The rubber strip material 1 has a ribbon shape with a flat cross-sectional shape mainly having a maximum thickness in the center in the width direction and gradually decreasing in thickness from the center toward both ends, for example, a substantially crescent shape in FIG. Or a ribbon shape having a cross-sectional shape such as a flat substantially trapezoidal shape in FIG. In the figure, W1 is the width of the rubber strip material 1, H1 is the maximum thickness of the rubber strip material 1, and R1 is the thickness at both ends in the width direction. Set to

  An extruder 10 constituting a molding apparatus for extruding the rubber strip material 1 includes a main body case 11 having a cylindrical cross section, a feed screw shaft 12 provided therein, and a distal end portion of the main body case 11. The rubber material Q is supplied to the inside of the main body case 11 from the hopper 16 and is supplied with a molding die 15 attached to the tip end side of the head portion 13 having a gear pump 14 connected to the head portion 13. Is fed forward by the rotation of the screw shaft 12 and is continuously extruded through a die 15 by a gear pump 14 of the head portion 13 so as to be extruded into a ribbon shape.

  And in the apparatus used for the molding method of the rubber strip material 1 of the present invention, the temperature adjustment temperature of each part of the head portion 13 including the main body case 11 of the extruder 10, the internal screw shaft 12 and the die 15 is made different. The temperature adjustment temperature of the main body case 11 is set higher than the temperature adjustment temperature of the screw shaft 12, and the temperature adjustment temperature of the head portion 13 is set higher than that of the main body case 11.

  In addition to the case where the temperature control temperature is set to the same temperature including the portion of the die 15 connected to the tip portion of the portion of the head portion 13, the portion of the die 15 is the portion of the head portion 13. Apart from that, the temperature control temperature of the die 15 may be set to be higher than the temperature control temperature of the head unit 13. That is, the temperature control temperature of the die 15 is set to be equal to or higher than the temperature control temperature of the head unit 13.

  In addition, the difference of the temperature control temperature of each part of the said main body case 11, the screw shaft 12, the head part 13, and the dice | dies 15 can be suitably set with the mixing | blending and kind of rubber material to be used, and temperature adjustment is commanded from a control part etc. It is configured so that it can be appropriately controlled by a signal or the like. Moreover, the said temperature control temperature shall be 50 degreeC minimum, and is normally set suitably in the range of 50 to 100 degreeC.

  Further, the die 15 is provided with a molding discharge port 17 which is continuous with the tip end portion of the inner hole portion 15a through the drawing step surface 18 at a substantially central portion of the step surface 18. The discharge port 17 is formed in a substantially crescent shape, a flat substantially triangular shape, and a flat substantially trapezoidal shape corresponding to the cross-sectional shape of the rubber strip material 1 to be molded illustrated in FIGS. 7, 8, and 9. In addition, the rubber material Q fed as described above is provided so as to be formed into a strip shape having a cross-sectional shape corresponding to the shape. In FIG. 3, W is the width of the discharge port 17, H is the maximum gap of the discharge port 17, and R is the gap at both ends of the width of the discharge port 17, and the width W1 and the maximum thickness of the rubber strip material 1 respectively. H1 corresponds to the thickness R1 at both ends of the width.

  The shape of the inner hole portion 15a of the die 15 may be a simple taper shape (for example, FIGS. 17 to 19) toward the drawing step surface 18 as in the prior art. In the invention, it is preferable to use the shape shown in FIGS.

  The die 15 of FIGS. 4 to 6 has an inner hole portion 15a in the middle of the flow direction of the inner hole portion 15a from the rear end opening 19 connected to the head portion 13 to the discharge port 17 in the inner hole portion 15a. In addition, an intermediate throttle part 25 is provided to provide a step difference between the rear end side inner hole part 15b and the front end side inner hole part 15c, and the intermediate throttle part 25 and the throttle step surface 18 at the front end part with respect to the rubber material Q. It is formed so that an aperture can be given.

  In particular, the front end side inner hole portion 15b is formed in a long hole shape corresponding to the longitudinal direction of the molding discharge port 17 when viewed from the rear end side, and is continuous with the throttle step surface 18 of the front end portion. Therefore, the throttle step surface 18 also has the same shape as the tip side inner hole portion 15b, and the discharge port 17 is formed at the center thereof. As shown in the figure, the front end side inner hole portion 15b and the rear end side inner hole portion 15c are not limited to one having a taper shape on one side (rear end side) and a non-taper shape on the other side (front end side), Either a tapered shape or a non-tapered shape may be used.

  The degree of restriction by the intermediate restricting portion 25, that is, the step amount between the front end side inner hole portion 15b and the rear end side inner hole portion 15c, the shape of the rubber strip material 1 to be molded, the type of rubber material, and the like However, in practice, the cross-sectional area of the opening portion of the intermediate throttle portion 25 is 20 to 50% of the cross-sectional area of the same portion due to the extension of the inner peripheral surface of the rear end side inner hole portion 15c. It is preferable to set the range, particularly 30 to 40%.

  That is, if the cross-sectional area of the intermediate throttle portion 25 is larger than the range, the effect of the throttle is difficult to be achieved, and if it is smaller than the range, the extrusion resistance of the rubber material increases. preferable.

  When the molding method of the rubber strip material 1 of the present invention is carried out using the molding apparatus, the rubber material Q put into the main body case 11 of the extruder 10 is sent by the screw shaft 12 to the head portion 13. And is continuously extruded in a ribbon shape from the discharge port 17 of the die 15 by the gear pump 14 of the head portion 13. Particularly, at this time, the temperature adjustment temperature of the main body case 11 is set higher than that of the screw shaft 12, and the temperature adjustment temperature of the head portion 13 is set higher than that of the main body case 11, so that the temperature of the rubber material Q is gradually increased. Passed through and pushed out.

  Therefore, even if the extrusion speed is not slowed as in the prior art, it is possible to suppress the occurrence of missing such as cracks and chips in the ear portions 1a and 1a at both ends of the width of the rubber strip material 1 to be extruded as described above. Moreover, it is possible to form the rubber strip material 1 which is wider than the conventional one and whose thickness at both side ends is thin without reducing the extrusion speed. For example, the rubber strip material 1 extruded by the molding die 13 has a width of 5 to 50 mm, a thickness at the center of the width of 0.5 to 3.0 mm, and thicknesses at both ends in the width direction of 0.05 to 0.00. Extrusion molding can be performed without any problem in a substantially crescent shape, a substantially triangular shape, or a substantially trapezoidal cross-sectional shape in a range of 2 mm.

  In particular, when the inner hole portion 15a of the die 15 of the extruder 10 has a drawing shape as shown in FIGS. The rubber strip material 1 can be formed significantly higher than the conventional-shaped die, and the extrusion speed can be increased, and the width and width of both ends are thinner than those of the conventional die.

  Table 1 below shows each part of the screw shaft 12, the body case 11, the head portion 13, and the die 15 of the extruder 10 for the rubber strip material 1 used for the inner liner rubber portion having high viscoelasticity that is required to be extremely thin. The comparison of the critical speed of the ear | edge part omission when the shaping | molding test was implemented by setting different temperature control temperature of the is shown.

  Table 2 below shows the temperature control of each part of the screw shaft 12, the body case 11, the head portion 13, and the die 15 of the extruder 10 for the rubber strip material 1 used for the tread rubber portion having relatively low viscoelasticity. The comparison of the limit speed | rate of an ear | edge part loss | missing at the time of implementing a shaping | molding test in different temperature settings is shown.

In Tables 1 and 2, the missing critical speed is indicated as an index with Comparative Example 1 in which the temperature control temperature of the part is kept constant as 100. Moreover, each alphabet of temperature control temperature is set to A, B, C, D, E, F, G, and H in order from the one with the highest temperature control temperature.

  As a result of the above Tables 1 and 2, the temperature control temperature of each part of the screw shaft 12, the main body case 11 and the head part 13 of the extruder 10 is set to be higher sequentially, compared with the comparative example in which the temperature control temperature is not changed. Thus, it was possible to increase the critical speed at which the ear part is lost by 30 to 50%. That is, it has been found that the molding method of the present invention in which the temperature control temperature of each part of the screw shaft 12, the main body case 11, and the head portion 13 is sequentially set higher and extrusion molding is effective in preventing the missing of the ear portion.

  It should be noted that there was no significant difference between the case where the temperature control temperature of the part of the die 15 was set higher than that of the part of the head portion 13 and the case where the temperature was set the same.

  Table 3 below is based on the results of Tables 1 and 2 above, and the difference in the die shape under the condition that the temperature control temperature of each part of the screw shaft 12, the main body case 11 and the head part 13 is sequentially set higher. The comparison of the critical speed of ear loss by is shown.

  In Table 3, Example 1 is a die for the inner liner rubber part, Example 2 is a die for the first layer of the tread rubber part, Example 3 is a die for the second layer of the tread rubber part, Example 4 Shows again a die for the wall rubber part, and Comparative Example 1 is a die for the rubber part having an inner hole part shape shown in FIGS. W, H, and R are the dimensions of the molding discharge port 17 of FIG. 3, the width is 5 to 50 mm, the thickness at the width central portion is 0.5 to 3.0 mm, and the thickness at both ends of the width is 0.05. The numerical values of H / R, W / R, and W are all shown as indexes with the die of the same member of the example being 100.

Further, in Table 3, the area of the intermediate throttle portion is the opening area at the position of the intermediate throttle portion 25 of the die inner hole portion shown in FIGS. 4 to 6, and the same position of the die inner hole portion of FIGS. 17 to 19. An opening area of 100 is shown as an index. Further, the ear missing limit speed is shown as an index with Comparative Example 1 being 100.

  As a result of the above Table 3, for the rubber strip material for the inner liner rubber part having high viscoelasticity, H / R is the same as that of the comparative example, and W / R and W are considerably larger than those of the comparative example, Even when the width is wide and the thickness at both ends of the width is reduced, the shape of the die inner hole is provided with an intermediate throttle portion, so that the critical speed limit of the ear portion is significantly larger than that of Comparative Example 1 ( 2 times or more).

  With respect to the rubber strip materials for other rubber members, it was possible to significantly increase the missing limit speed of the ear portion as compared with the comparative example.

  Therefore, the extrusion speed of the rubber strip material of each rubber member can be increased more than before without fear of missing ear parts, and a wider and thinner rubber strip material can be molded without fear of missing ear parts. It becomes possible to do.

  A method of manufacturing a tire using the rubber strip material 1 molded as described above will be described.

  FIG. 10 shows an inner liner rubber part 2, a tread rubber part 3, and a side wall rubber by winding a rubber strip material 1 extruded from the extruder in the tire manufacturing process on a rotary support 20 such as a molding drum. It is a schematic diagram for demonstrating the method to shape | mold the rubber member for tires, such as the part 4 and the rim strip rubber part 5. FIG.

  In the case of FIG. 10, the extruder 10 is placed opposite to the rotary support 20, and the rubber strip material 1 extruded from the extruder 10 into a ribbon shape having a predetermined cross-sectional shape is directly placed on the rotary support 20. The case of winding 2 is shown. The rotary support 20 is rotatable around a shaft 20a, and the rubber strip material 1 is wound around the tire circumferential direction while rotating the rotary support 20 in the K direction in FIG.

  FIG. 11 is a view of the rotary support 20 as viewed from above. The arrow A corresponds to the tire circumferential direction, and the arrow B direction corresponds to the tire width direction (axial direction). The rubber strip material 1 is wound spirally along the tire circumferential direction. When the rubber strip material 1 is wound, not only the rotating support 20 is rotated, but also the extruder 10 is relatively moved along the tire width direction B. Therefore, either the extruder 10 or the rotary support 20 is moved along the tire width direction.

In the example of FIG. 11, the rubber strip material 1 is wound while moving from the left side to the right side. The first round (Volume 1) is M ₁ , the second round is M ₂ , the third round is M _{3, and the} n-1 round is M _n-1.
, N-th cycle (final) is denoted by M _{n .} Wherein the first lap M ₁ and n-th revolution M _n, the winding direction is the same as the direction perpendicular to the tire width direction (parallel to the tire circumferential direction). Since the other portions are wound spirally, the winding direction is inclined by an angle α with respect to the tire circumferential direction. If the first lap and the last n laps are also tilted at an angle α, it will be necessary to cut off the excess part. This eliminates the need for the process of cutting the excess part.

  About the first 1st round and the last nth round, if it controls so that the extruder 10 may not move relatively along a tire width direction, it can be set as the above structures. The control device 30 controls the operation of the extruder 10 and the rotary support 20.

Further, in FIG. 11, the winding start position is at P _S, winding end position is indicated by P _E. Then, positional deviation of the end position P _E winding the winding start position P _S delta is wound so as to 0~5mm when viewed from the tire circumferential direction. Thereby, the weight balance of a tire can be maintained favorable.

  FIG. 12 is a diagram illustrating how the rubber strip members 1 are stacked in the tire width direction. The adjacent rubber strip materials 1 and 1 preferably overlap each other by about 1/2 (half) to 1/5 of the width W1 of the rubber strip material 1 (see FIGS. 12A and 12B). . This is because if the width is less than or equal to ½ of the width W1, the unevenness when stacked is inconspicuous. Further, the reason why the width W1 is 1/5 or more is that if the overlap is further reduced, the rubber strip material 1 may be scattered. The degree of overlap is controlled by controlling the relative movement speed in the tire width direction between the extruder 10 and the rotary support 20 by the control device 30.

  As described above, the shape of the rubber member can be accurately manufactured by changing the overlapping state of the adjacent rubber strip materials or the cross-sectional shape. In particular, by using the rubber strip material 1 molded as described above, molding can be performed with higher accuracy, and both quality tires can be manufactured.

  FIG. 13 is a view showing a preferable arrangement of the winding start position when a plurality of rubber members are molded by winding the rubber strip material 1. In FIG. 13, the winding start position of the inner liner rubber part 2 is T1, the winding start position of the tread rubber part 3 is T2, the winding start position of the sidewall rubber part 4 is T3, and the winding start position of the rim strip rubber part 5 is T4. Is shown schematically. If the positions of T1, T2, T3, and T4 are concentrated at the same position, the balance characteristic may be deteriorated. Therefore, it is preferable that the phase shift in the tire circumferential direction at each start position (indicated by θ in FIG. 14) is 10 degrees or more. In the example shown in the figure, the phase shift at each start position is made equal to θ = 90 degrees.

  Moreover, since the tread rubber portion 3 is constituted by using two types of rubber strip materials of the first layer and the second layer, the winding start position when winding the rubber strip material of the first layer (lower layer), Similarly, with respect to the winding start position when the rubber strip material of the second layer (upper layer) is wound, it is preferable that the phase shift in the tire circumferential direction at the start position is 10 degrees or more.

  Since the winding end position is a deviation of 0 to 5 mm from the winding start position, if the phase shift at the winding start position is set to 10 degrees or more, the phase shift is similarly set to 10 degrees or more at the winding end position.

  Thus, by wrapping the rubber strip material 1 and molding each rubber member, the tire performance such as weight balance can be favorably maintained.

  In the above description of the molding method, the rubber strip material 1 extruded from the extruder 10 is supplied to the rotary support 20 such as a molding drum at the same time as the extrusion, and the winding molding absence is shown. It is also possible to extrude the rubber strip material in a separate process from the winding process, transfer it to the winding molding process, and continuously feed it onto the rotating support via the supply device. Is possible.

  The present invention molds a rubber member for a tire by winding an unvulcanized rubber strip material extruded in a ribbon shape on a rotating support such as a molding drum in a spiral manner along the circumferential direction of the tire. Thus, it can be suitably used when manufacturing a tire.

It is a schematic side view of the extruder which comprises the shaping | molding apparatus used in the shaping | molding method of the rubber strip material of this invention. It is sectional explanatory drawing of an extruder same as the above. It is a schematic front view illustrating the shape of a die forming discharge port. It is a front view from the rear end side of a die | dye same as the above. It is a cross-sectional explanatory drawing of the VV line of FIG. 4 which shows the inner-hole part shape of a die | dye same as the above. It is a section explanatory view of the VI-VI line of Drawing 4 showing the shape of an inner hole of a die same as the above. It is sectional drawing which shows an example of the cross-sectional shape of the rubber strip material of a shaping | molding object. It is sectional drawing which shows the other example of the cross-sectional shape of a rubber strip material same as the above. It is sectional drawing which shows the further another example of the cross-sectional shape of a rubber strip material same as the above. It is a schematic diagram for demonstrating the method of winding the rubber strip material extrusion-molded by an extruder, and shape | molding a rubber member. It is a top view explaining the winding method of a rubber strip material. It is sectional drawing explaining how to laminate | stack a rubber strip material. It is explanatory drawing which illustrates the preferable position of the winding start position of each rubber member. It is explanatory drawing of the winding start position of a rubber member same as the above. It is sectional drawing for demonstrating a tire structure. It is a schematic side view of a head portion of an extruder for extruding a conventional rubber strip material. It is a front view from the rear end side of a die | dye same as the above. It is sectional explanatory drawing explaining the inner-hole part shape of a die | dye same as the above. It is side sectional explanatory drawing which shows the inner-hole part shape of a die | dye same as the above.

Explanation of symbols

T tire Q rubber material 1 rubber strip material 2 inner liner rubber part 3 tread rubber part 4 sidewall rubber part 5 rim strip rubber part 10 extruder 11 main body case 12 screw shaft 13 head part 14 gear pump 15 die 15a inner hole part 15b tip Side inner hole portion 15c Rear end side inner hole portion 16 Hopper 17 Molding outlet 18 Drawing step surface 19 Rear end opening 20 Rotating support 25 Intermediate throttle 30 Controller

Claims (11)

A method of molding the rubber strip material used in a tire manufacturing process in which a tire rubber member is molded by spirally winding an unvulcanized rubber strip material extruded from a molding die of an extruder,
The temperature control temperature of the main body case is higher than that of the screw shaft by differentiating the temperature control temperature of each part of the main body case of the extruder, the internal screw shaft and the head including the dice, and further than the main body case. A method for molding a rubber strip material for tire manufacture, wherein the temperature control temperature of the head portion is set high and the rubber material is continuously extruded in a ribbon shape.   The method for molding a rubber strip material for tire production according to claim 1, wherein extrusion molding is performed by setting a temperature control temperature of the die to be equal to or higher than a temperature control temperature of the head portion.   The rubber strip material extruded by the molding die has a cross-sectional shape in which the thickness is gradually reduced from the width center portion toward the width sides, the width is 5 to 50 mm, and the thickness of the width center portion is 0.5 to 3.0 mm. 3. A method for molding a rubber strip material for tire production according to claim 1 or 2, wherein extrusion is performed in a ribbon shape having a thickness at both side ends in the range of 0.05 to 0.2 mm. A rubber strip material molding apparatus used in a tire manufacturing process in which a tire rubber member is molded by spirally winding an unvulcanized rubber strip material extruded from a molding die of an extruder,
The temperature control temperature of the main body case is higher than that of the screw shaft, and the temperature control temperature of the main body case is higher than that of the screw shaft. An apparatus for molding a rubber strip material, wherein the temperature adjustment temperature of the head portion is set to be high.   The apparatus for molding a rubber strip material according to claim 4, wherein the temperature control temperature of the die is set to be equal to or higher than the temperature control temperature of the head portion.   The molding die is provided with a molding discharge port continuous at the front end portion of the inner hole portion thereof through a drawing step surface, and the rear end opening connected to the head portion leads to the discharge port. An intermediate throttle portion is provided in the middle of the inner hole portion in the flow direction so as to make a step difference between the rear end side inner hole portion and the front end side inner hole portion. 6. The rubber strip material molding apparatus according to claim 4, wherein the rubber strip material is configured so as to be constricted with the stepped surface.   The front end side inner hole portion is formed in a long hole shape corresponding to the longitudinal direction of the molding discharge port as viewed from the rear end side, and is continuous with the drawing step surface of the front end portion. Rubber strip material molding equipment.   In the manufacturing method of the tire comprised from the rubber member for tires, about the at least 1 said rubber member, it has not been extruded from the die | dye of the extruder by the method of any one of the said Claims 1-3. A rubber member for a tire having a predetermined shape is formed by supplying a rubber strip material for vulcanization onto a rotating support for molding a tire and winding a part of the rubber strip in a spiral shape in the circumferential direction of the tire. A method for manufacturing a tire.   The tire manufacturing method according to claim 8, wherein the rubber strip material is molded so that a positional deviation between a winding start position and a winding end position is in a range of 0 to 5 mm in the tire circumferential direction.   The tire manufacturing method according to claim 8 or 9, wherein the rubber strip material is wound so that an overlapping amount in a tire width direction is 1/2 to 1/5 of a width dimension of the rubber strip material. At least two rubber members among a plurality of tire rubber members are formed by spirally winding a rubber strip material corresponding to each rubber member in each winding step in the tire circumferential direction,
The method for manufacturing a tire according to any one of claims 8 to 10, wherein the winding start position for each rubber strip material is shifted in the tire circumferential direction, and the winding is molded by setting the phase shift to 10 degrees or more. .

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