JP6123280B2 - Bias tire manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a method and an apparatus for manufacturing a bias tire, and more particularly, to a method and an apparatus for manufacturing a bias tire that can reduce uneven thickness of a cap tread.

  Conventionally, when manufacturing a pneumatic tire having a bias structure, first, a tire frame member including a carcass layer having a bias structure is formed into a cylindrical shape, and a sheet-like cap tread member is wound around the outer peripheral side thereof to form an elongated shape. A cylindrical green tire is formed. Next, the green tire molded in this way is put into a mold, and the mold is inflated with the expansion of the bladder in the shaping process, and the mold is placed with the outer diameter of the green tire approaching the outer diameter of the final shape. Is closed, and then the green tire is vulcanized (see, for example, Patent Documents 1 to 3).

  However, the bias tire manufactured as described above has a problem that the thickness of the cap tread tends to be uneven. That is, in the bias tire manufacturing method described above, the cord angle so that the cord angle of the carcass layer in the tread portion of the product tire that has undergone the shaping process is smaller than the cord angle of the carcass layer in the tire frame member with respect to the tire circumferential direction. Changes. Therefore, the sheet-like cap tread member has a shape that is wider and thinner than the cap tread in the product tire, and the cap tread approaches the final product size as the tire shape changes. Such a wide and thin cap tread member has a large variation in thickness at the time of extrusion, and the variation in thickness tends to be amplified with a change in the tire shape in the manufacturing process, and as a result The thickness of the cap tread in the product tire becomes uneven. In addition, when a cap tread member having a wide width and a small thickness is wound around a tire frame member, it is common to perform a crimping operation using a stitcher. Such a stitcher hook also has a thickness of the cap tread member. It becomes non-uniform, and it becomes a factor which makes the thickness of the cap tread in a product tire non-uniform | heterogenous.

JP-A-2005-212140 JP 2010-18010 A Japanese Patent No. 3634833

  An object of the present invention is to provide a bias tire manufacturing method and a manufacturing apparatus capable of reducing non-uniform thickness of a cap tread.

In order to achieve the above object, a method for manufacturing a bias tire according to the present invention comprises a pair of side molds for molding a side portion of a bias tire and a mold including an annular tread mold for molding the tread portion of the bias tire. A cylindrical bladder disposed in the mold, a first position defined at a position where the tread mold is removed from the pair of side molds, and the pair of side molds A method of manufacturing a bias tire using a tire manufacturing apparatus including a transfer device that moves to a specified second position and a third position specified to a position in close contact with one side mold. ,
A tire frame member including a carcass layer having a bias structure is formed into a cylindrical shape, a cap tread member having an inner diameter larger than the outer diameter of the tire frame member is formed into an annular shape, and the tread mold is formed at the first position. The cap tread member is disposed on the inner peripheral surface of the tire, the tread mold having the cap tread member is moved to the second position by the transfer device, and the tire frame member is disposed around the bladder. The tire skeleton member is inflated by inflating the bladder to press the tire skeleton member against the cap tread member, and the third tread mold is moved by the transfer device according to the expansion of the bladder. Move to position and move the tread mold to the third position Closing said mold I is a green tire comprising a single piece of the cap tread member and the tire frame member which is characterized in that vulcanizing in the mold.

  Furthermore, a bias tire manufacturing apparatus according to the present invention for achieving the above object includes a pair of side molds for molding a side portion of the bias tire and an annular tread mold for molding the tread portion of the bias tire. A mold, a cylindrical bladder disposed in the mold, a first position defined at a position where the tread mold is separated from the pair of side molds, and the pair of side molds; And a transfer device that moves to a second position defined in between and a third position defined at a position in close contact with one of the side molds.

  In the present invention, when manufacturing a bias tire, an annular cap tread member and a cylindrical tire frame member are separately molded, and both members are pressure-bonded to each other in a mold, and the cap tread member and the tire frame member are Since the green tire made of a single piece is vulcanized as it is in the mold, the conventional stitcher hook is unnecessary, and the uneven thickness of the cap tread due to the stitcher hook can be reduced. . In addition, in the conventional bias tire manufacturing method, a cap tread member having a wide width and a small thickness is used as a starting material. However, in the present invention, a cap tread member that approximates the final shape of the cap tread of a product tire is used. Is possible. Therefore, by using the thick cap tread member extruded with high accuracy, it is possible to reduce the uneven thickness of the cap tread in the product tire.

  If the thickness of the cap tread is not uniform along the tire width direction, the thick portion will generate heat locally during driving, and the cap tread will be easily damaged, and the thickness of the cap tread will extend along the tire circumferential direction. If it is non-uniform, vibration is likely to occur during traveling, but it is possible to eliminate these disadvantages by reducing the non-uniform thickness of the cap tread as described above.

  In the present invention, a mold including a pair of side molds for molding the side portion of the bias tire and an annular tread mold for molding the tread portion of the bias tire, and a cylindrical shape disposed in the mold The bladder and the tread mold are in close contact with the first position defined between the pair of side molds and the second position defined between the pair of side molds and the one side mold. It is preferable to use a tire manufacturing apparatus including a transfer device that moves to a third position defined by the position.

  In this case, a tire frame member including a carcass layer having a bias structure is formed into a cylindrical shape, and a cap tread member having an inner diameter larger than the outer diameter of the tire frame member is formed into an annular shape, and then the tread in the first position. A cap tread member is arranged on the inner peripheral surface of the mold, the tread mold having the cap tread member is moved to the second position by the transfer device, a tire frame member is arranged around the bladder, and the bladder is inflated. Then, the tire frame member is inflated to press the tire frame member against the cap tread member. Then, the tread mold is moved to the third position by the transfer device as the bladder expands, and the mold is closed as the tread mold is moved to the third position, and the cap tread member and the tire frame member are integrated. A green tire made of material is vulcanized as it is in a mold. Thereby, the manufacturing method of the bias tire mentioned above can be implemented easily.

  In the tire manufacturing apparatus, the transfer device holds the tread mold so as to be pivotable so that the direction of the central axis thereof is changed, and the tread mold is composed of a plurality of divided pieces, and the connecting portions of the divided pieces are connected to each other. It is preferable to have a structure in which at least one is separable. In this case, when the cap tread member is arranged on the inner peripheral surface of the tread mold at the first position, the direction of the central axis of the tread mold is set to an arbitrary direction, and at least one of the connecting portions of the split pieces is set. Separate and leave the tread mold open. Thereby, the process of arrange | positioning a cap tread member on the internal peripheral surface of a tread shaping | molding die can be performed smoothly.

  In the tire manufacturing apparatus, the tread mold preferably has a plurality of protrusions on its inner peripheral surface. In this case, when the cap tread member is disposed on the inner peripheral surface of the tread mold at the first position, the protrusion is protruded into the cap tread member. Thereby, the transfer from the 1st position of a cap tread member to the 3rd position can be stabilized.

  In the tire manufacturing apparatus, the tread mold preferably has a heating means. In this case, the heating means is turned off when the tread mold is in the first position, and the heating means is turned on when the tread mold is in the third position. Thus, when the cap tread member is transferred from the first position to the third position, the cap tread member is maintained in a highly rigid state, and during the vulcanization at the third position, the temperature rise of the cap tread member is promoted, A necessary amount of heat can be supplied to a necessary part.

  The manufacturing method and manufacturing apparatus for a bias tire according to the present invention is preferably applied to a bias tire for a racing cart in which the uniformity of the cap tread thickness is particularly important.

It is sectional drawing which shows the principal part of the manufacturing apparatus of the bias tire which consists of embodiment of this invention. It is a side view which shows the transfer apparatus of FIG. It is a side view which shows the other operation state of the transfer apparatus of FIG. The manufacturing method of the bias tire which consists of embodiment of this invention is shown, (a)-(d) is a schematic sectional drawing of each process. It is a top view which shows the modification of a tread mold. It is a perspective view which shows the principal part of the tread mold of FIG. It is a side view which shows the protrusion formed in the inner peripheral surface of the tread mold of FIG. It is a top view which shows the protrusion formed in the internal peripheral surface of the tread mold of FIG.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 show an apparatus for manufacturing a bias tire according to an embodiment of the present invention.

  As shown in FIG. 1, the tire manufacturing apparatus includes a side mold 1 (lower mold) for molding one side portion of a pneumatic tire (bias tire) and a side for molding the other side portion of the pneumatic tire. A mold 10 including a mold 2 (upper mold) and an annular tread mold 3 for molding a pneumatic tire tread portion is provided. When the mold 10 including the side molds 1 and 2 and the tread mold 3 is closed, a cavity for molding a pneumatic tire is formed inside the mold 10. Arbitrary groove patterns and the like can be formed on the molding surfaces of the side molds 1 and 2 and the tread mold 3 as necessary.

  The lower side mold 1 is installed on the upper surface of the support plate 5 via the lower heating device 4. On the other hand, the upper side mold 2 is installed on the lower surface of the movable plate 7 via the upper heating device 6. The movable plate 7 is supported by a driving device (not shown) so as to be movable in the vertical direction. Further, the tread mold 3 is disposed so as to be fitted into an annular notch formed in the side molds 1 and 2. Therefore, the side molds 1 and 2 are in close contact with each other when the mold 10 including the side molds 1 and 2 and the tread mold 3 is closed.

  The tread mold 3 is supported by a transfer device 11. The transfer device 11 includes a drive unit 12 erected in the vicinity of the mold 10 and an arm 13 extending in the horizontal direction from the drive unit 12. The drive unit 12 is configured to be rotatable about a vertical axis, and the arm 13 is configured to be movable in the vertical direction with respect to the drive unit 12. Therefore, the transfer device 11 is based on the operation of the drive unit 12 and the arm 13, as shown in FIG. 2, in the first position defined at a position where the tread mold 3 is removed from the pair of side molds 1 and 2. It can be moved to a second position P2 defined between P1 and the pair of side molds 1 and 2, and a third position P3 defined at a position in close contact with one side mold 1. FIG. 1 depicts a state in which the tread mold 3 is located at the second position P2.

  The transfer device 11 holds the tread mold 3 so as to be rotatable so that the direction of the central axis thereof is changed. Such turning of the tread mold 3 is performed by the rotation of the arm 13. Therefore, as shown in FIG. 3, at the first position P1, for example, the tread mold 3 can be arranged so that the direction of the central axis is the horizontal direction. Further, the tread mold 3 is composed of a plurality of divided pieces 3a, and has a structure in which at least one of the connecting portions of the divided pieces 3a is separable. In FIG. 3, one end of two arcuate pieces 3a and 3a are connected to each other via a hinge 14, and the other ends of these pieces 3a and 3a are arbitrarily released. .

  In this case, when the cap tread member T1 made of a rubber composition is gripped on the inner peripheral surface of the tread mold 3 at the first position P1, the direction of the central axis of the tread mold 3 is set to an arbitrary direction and divided. The tread mold 3 can be opened by separating at least one of the connecting portions of the pieces 11a and 11b. Therefore, the step of arranging the cap tread member T1 on the inner peripheral surface of the tread mold 3 can be performed smoothly.

  As shown in FIG. 1, a heating device 15 is embedded in the tread mold 3 as a heating means. The configuration of such a heating device 15 is not particularly limited. For example, resistance heating or the like that embeds a conductor having resistance in the tread mold 3 and energizes the conductor to generate heat. A dielectric sandwiched between electrodes is embedded in the tread mold 3 and dielectric heating is performed to heat the dielectric by applying a high frequency voltage between the electrodes. It is possible to employ induction heating that heats a conductor disposed in the vicinity of the winding by being embedded in the winding and passing an alternating current through the winding. It is also possible to form a heat medium flow path inside the tread mold 3 and introduce the heat medium into the flow path. In this case, it is possible to use both the heating means and the cooling means.

  A cylindrical bladder 21 is coaxially disposed between the pair of side molds 1 and 2 with respect to the side molds 1 and 2. The lower end portion of the bladder 21 is fixed to the lower clamp member 22, and the upper end portion of the bladder 21 is fixed to the upper clamp member 23. The bladder 21 is expanded and contracted in the tire axial direction by a bladder driving device 24. In other words, the bladder driving device 24 includes a hydraulic cylinder 25 and a piston rod (center post) 26, and the piston rod 26 includes the support plate 5, the lower heating device 4, the lower side molding die 1, and the lower clamping member 22. And is connected to the upper clamp member 23. Although FIG. 1 shows a state in which the bladder 21 extends in the tire axial direction, expansion of the bladder 21 in the tire radial direction is permitted when the bladder 21 is contracted in the tire axial direction.

  An intake passage 27 communicating with the internal space of the bladder 21 is connected to an intake pipe 28 on the lower side of the support plate 5, and further connected to a pressurized medium supply source 30 via a valve 29. A pressurized medium such as steam or nitrogen gas is supplied from the pressurized medium supply source 30, but these pressurized media can be supplied by a plurality of systems. On the other hand, an exhaust passage 31 communicating with the internal space of the bladder 21 is connected to an exhaust pipe 32 on the lower side of the support plate 5 and is further discharged to the outside through a valve 33. The intake passage 27, the intake pipe 28, the valve 29, the pressurized medium supply source 30, the exhaust passage 31, the exhaust pipe 32, and the valve 33 constitute a pressure adjusting device 34.

  The tire manufacturing apparatus includes a control device 35 that controls the transfer device 11, the bladder driving device 24, and the pressure adjusting device 34. In addition to controlling the movement of the tread mold 3 by the transfer device 11, the control device 35 always keeps the tread mold 3 in the width direction of the bladder 21 when the bladder driving device 24 decreases the width W of the bladder 21. The transfer device 11 is controlled so as to be arranged at the center position of the. That is, the height H from the lower end portion of the bladder 21 to the center position in the width direction of the tread mold 3 is controlled so as to be always ½ of the width W of the bladder 21.

  Next, a method for manufacturing a bias tire using the above-described tire manufacturing apparatus will be described in detail with reference to FIGS.

  First, as shown in FIG. 4 (a), a tire frame member T2 including a carcass layer having a bias structure is formed into a cylindrical shape, while a cap tread member having an inner diameter larger than the outer diameter of the tire frame member T2. T1 is formed in an annular shape, and the cap tread member T1 is disposed on the inner peripheral surface of the tread mold 3 at the first position P1. The outer diameter of the cylindrical tire frame member T2 may be set in a range of 50% to 85% with respect to the inner diameter of the cap tread member T1 formed in an annular shape. On the other hand, the thickness of the cap tread member T1 can be approximated to the final product dimension. For example, the thickness of the cap tread member T1 may be set in a range of 100% to 110% with respect to the cap tread thickness of the final product. The cap tread member T1 can be easily disposed inside the tread mold 3 based on the operation shown in FIG.

  Next, as shown in FIG. 4B, the tread mold 3 having the cap tread member T1 is moved to the second position P2 by the transfer device 11, while the tire frame member T2 is disposed around the bladder 21. To do. That is, the cap tread member T1 and the tire frame member T2 are arranged in the mold 10 in a state where they are coaxial and spaced apart from each other. At that time, the height H from the lower end portion of the bladder 21 to the center position in the width direction of the tread mold 3 is set to ½ of the width W of the bladder 21.

  Next, as shown in FIG. 4C, the bladder 21 is moved in the tire radial direction by gradually decreasing the width W of the bladder 21 by the bladder driving device 24 while increasing the pressure in the bladder 21 by the pressure adjusting device 34. The tire frame member T2 is deformed as the bladder 21 expands, and the tire frame member T2 is pressure-bonded to the cap tread member T1. At that time, the transfer is performed so that the tread mold 3 is always arranged at the center position in the width direction of the bladder 21, that is, the height H of the tread mold 3 is always ½ of the width W of the bladder 21. The tread mold 3 is displaced in the tire axial direction by the device 11. Such control is performed by the control device 35. Then, as the bladder 21 expands, the tread mold 3 moves to a third position P3 that is defined as a position in close contact with the lower side mold 1.

  Next, as shown in FIG. 4 (d), the mold 10 is closed with the movement of the tread mold 3 to the third position P3, and the green composed of the cap tread member T1 and the tire frame member T2 is integrated. The tire T is vulcanized in the mold 10.

  In the bias tire manufacturing method described above, an annular cap tread member T1 and a cylindrical tire skeleton member T2 are separately molded, and both the members T1 and T2 are pressure-bonded to each other in the mold 10, and these cap tread members T1. In addition, since the green tire T, which is an integral part of the tire frame member T2, is vulcanized in the mold 10 as it is, the conventional stitcher hook is unnecessary and the thickness of the cap tread due to the stitcher hook is reduced. Uniformity can be reduced.

  In the bias tire manufacturing method described above, it is possible to use the cap tread member T1 that approximates the final shape of the cap tread of the product tire. Therefore, by using the thick cap tread member T1 extruded with high accuracy, unlike the conventional case where the cap tread member having a wide width and a small thickness is used as a starting material, the cap tread in the product tire is Thickness non-uniformity can be reduced.

  Furthermore, in the bias tire manufacturing method described above, the tread mold 3 is configured independently of the side molds 1 and 2. For example, the tread width and the tread radius are set by sharing the structure of the side portion of the tire. When changing, only the tread mold 3 can be changed. Therefore, tires of a plurality of sizes can be vulcanized while using the side molds 1 and 2 in common. And since the joint of the metal mold | die 10 can be removed from the tread part of a tire, there also exists an advantage that the partial wear which starts a joint can be suppressed.

  Further, in the bias tire manufacturing method described above, the heating device 15 is attached to the tread mold 3, but when the tread mold 3 is in the first position P <b> 1, the heating device 15 is turned off, and the tread mold When 3 is in the third position P3, the heating device 15 is turned on. As a result, when the cap tread member T1 is transferred from the first position P1 to the third position P3, the cap tread member T1 can be maintained in a highly rigid state, so that the cap tread member T1 is transferred in a stable state. can do. On the other hand, at the time of vulcanization at the third position P3, the temperature rise of the cap tread member T1 can be promoted, and a necessary amount of heat can be supplied to a necessary portion.

  Further, when the cap tread member T1 is heated at the third position P3, the adhesiveness of the cap tread member T1 before being integrated with the tire frame member T2 can be increased, and based on the shaping pressure without performing stitchering. Thus, there is an advantage that the mutual adhesiveness when the cap tread member T1 and the tire frame member T2 are integrated can be enhanced. The heating device 15 may be turned on at an arbitrary timing while the tread mold 3 is moved from the first position P1 to the third position P3.

  In the above-described embodiment, the swing device is exemplified as the transfer device 11 of the tread mold 3, but the configuration of the transfer device 11 is not particularly limited, and the tread mold 3 is moved to the first position. Any device that can move from P1 to the third position P3 may be used. Of course, the transfer device 11 can be composed of a plurality of devices.

  In the above-described embodiment, the green tire molding process is smoothly performed based on the control by the control device 35. However, the operator does not rely on the control device 35, and the operator can transfer the transfer device 11, the bladder driving device 24, and the pressure. It is also possible to manually operate at least a part of the adjusting device 34.

  5 to 8 show modifications of the tread mold. 5 to 8, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 5 and 6, the tread mold 3 is composed of a plurality of divided pieces 3a, and has a structure in which at least one of the connecting portions of the divided pieces 3a is separable. A plurality of protrusions 16 are disposed on the inner peripheral surface of the tread mold 3. In particular, the protrusions 16 are preferably arranged at at least three locations on the circumference of the tread mold 3. In this case, when the cap tread member T1 is held on the inner peripheral surface of the tread mold 3 at the first position P1, the protrusion 16 is caused to enter the cap tread member T1. Thereby, the transfer of the cap tread member T1 from the first position P1 to the third position P3 can be stabilized.

  The shape of the protrusion 16 is not particularly limited. For example, it can be a columnar shape that forms a cylinder, an ellipse, or a polygon including a triangle in plan view, and in particular, the area of the top surface is made smaller than the area of the bottom surface. It is preferable to use a weight shape. Among them, as shown in FIGS. 7 and 8, it is most preferable to adopt an elliptical cone shape in which the area of the upper surface is smaller than the area of the bottom surface as the shape of the protrusion 16. The height X of the protrusion 16 is set in the range of 2 mm ≦ X ≦ 6 mm, the ratio of the top surface area U to the bottom surface area B is set in the range of 1 ≦ B / U ≦ 9, and the long diameter L and the short length are set. The ratio with the diameter S is preferably set in the range of 1 ≦ L / S ≦ 16.

  Such a protrusion 16 has a role of stabilizing the gripping of the cap tread member T1, and thereby a hole formed in the tread of the product tire can be used as a wear indicator.

  In the conventional bias tire manufacturing method, when a molding pin for molding a wear indicator is installed on the inner surface of the mold, the molding pin inhibits the rubber flow and a crack-like defect portion is formed in the vicinity of the wear indicator. However, according to the bias tire manufacturing method of the present invention, there is almost no rubber flow in the tread portion, so that no crack-like defect portion is formed in the vicinity of the wear indicator.

  Therefore, by utilizing such characteristics, in the rear wheel bias tire for driving, the ellipsoidal protrusions 16 are arranged so that the major axis is in the tire circumferential direction, and the tires are elongated along the tire circumferential direction. It is preferable to form a wear indicator as a scale. In this case, the driving force of the rear wheel bias tire provided with the wear indicator can be maximized. Further, in a bias tire for a front wheel that is responsible for steering, a protrusion 16 having an elliptical cone shape is disposed so that the major axis is in the tire width direction, and a wear indicator that is elongated along the tire width direction can be formed. preferable. In this case, the steering performance of the bias tire for the front wheels provided with the wear indicator can be maximized.

  When manufacturing a racing cart bias tire having a tire size of 7.1 × 11.0-5, 20 tires (examples) are manufactured based on the manufacturing method of the present invention, while the conventional two-part split type is manufactured. 20 tires (conventional example) were manufactured using a vulcanizer equipped with a mold.

  For these examples and conventional examples, the thickness (mm) of the cap tread was measured at eight locations on the tire circumference at the center position and shoulder position of the tread portion of each tire, and the average value μ (mm) and the standard deviation σ were determined. The results are shown in Table 1.

  As can be seen from Table 1, in the tire of the example, the non-uniformity of the thickness of the cap tread was reduced in comparison with the conventional example.

1, 2 Side mold 3 Tread mold 11 Transfer device 15 Heating device 16 Protrusion 21 Bladder T1 Cap tread member T2 Tire frame member T Green tire

Claims (8)

A mold including a pair of side molds for molding the side portion of the bias tire, an annular tread mold for molding the tread portion of the bias tire, and a cylindrical bladder disposed in the mold; The tread mold is closely attached to a first position defined at a position deviated from the pair of side molds and a second position defined between the pair of side molds and one side mold. A method of manufacturing a bias tire using a tire manufacturing apparatus including a transfer device that moves to a third position defined by a position,
A tire frame member including a carcass layer having a bias structure is formed into a cylindrical shape, a cap tread member having an inner diameter larger than the outer diameter of the tire frame member is formed into an annular shape, and the tread mold is formed at the first position. The cap tread member is disposed on the inner peripheral surface of the tire, the tread mold having the cap tread member is moved to the second position by the transfer device, and the tire frame member is disposed around the bladder. The tire skeleton member is inflated by inflating the bladder to press the tire skeleton member against the cap tread member, and the third tread mold is moved by the transfer device according to the expansion of the bladder. Move to position and move the tread mold to the third position Closing said mold I, the production method of a bias tire, wherein a green tire comprising a single piece of the cap tread member and the tire frame members vulcanized within the mold. In the tire manufacturing apparatus, the transfer device holds the tread mold so as to be rotatable so that the direction of the central axis thereof is changed, and the tread mold is composed of a plurality of divided pieces. It has a structure that makes at least one of the connecting portions separable,
When the cap tread member is disposed on the inner peripheral surface of the tread mold in the first position, the direction of the central axis of the tread mold is set to an arbitrary direction, and at least one of the connecting portions of the divided pieces is set. The bias tire manufacturing method according to claim 1 , wherein the tread mold is opened by separating the two. In the tire manufacturing apparatus, the tread mold has a plurality of protrusions on an inner peripheral surface thereof, and the cap tread member is disposed when the cap tread member is disposed on the inner peripheral surface of the tread mold at the first position. The method for manufacturing a bias tire according to claim 2 , wherein the protrusion is inserted into the member. In the tire manufacturing apparatus, the tread mold has a heating means,
Claim 1 wherein when the tread mold is in the first position is turned off the heating means, when the tread mold is in the third position, characterized in that the ON state of said heating means The manufacturing method of the bias tire in any one of -3 .   A mold including a pair of side molds for molding the side portion of the bias tire, an annular tread mold for molding the tread portion of the bias tire, and a cylindrical bladder disposed in the mold; The tread mold is closely attached to a first position defined at a position deviated from the pair of side molds and a second position defined between the pair of side molds and one side mold. A bias tire manufacturing apparatus, comprising: a transfer device that moves to a third position defined by a position. The transfer device holds the tread mold so as to be rotatable so that the direction of the central axis thereof is changed, and the tread mold is composed of a plurality of divided pieces, and at least one of the connecting portions of the divided pieces. The apparatus for manufacturing a bias tire according to claim 5 , wherein the apparatus has a structure that allows separability. The bias tire manufacturing apparatus according to claim 6 , wherein the tread mold has a plurality of protrusions on an inner peripheral surface thereof. The bias tire manufacturing apparatus according to any one of claims 5 to 7 , wherein the tread mold includes a heating unit.

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