JP4731210B2 - Rubber strip lamination molding method - Google Patents

Description

  The present invention relates to a method of forming a laminated member by winding a rubber strip material around a core drum.

  As this rubber strip lamination molding method, a method of directly molding a tire constituent member by winding a rubber strip material around a tire molding drum has already been proposed (see, for example, Patent Document 1).

JP 2003-326612 A

  Conventionally, when molding a tire constituent member, a rubber strip material of a predetermined shape is supplied to the tire molding drum at a constant ratio between the extrusion speed of the rubber strip material of the extruder and the winding speed of the tire molding drum. I am doing so.

  In Patent Document 1, a plurality of injection speeds of the injection molding machine and rotation speeds (winding speeds) of the tire molding drum are used to solve problems such as shrinkage of the extruded rubber member at the initial stage of injection by the injection molding machine (extruder). Although the control is performed to raise each through the stages, this is also to stably wrap the extruded rubber member around the tire molding drum from the initial injection stage. The speed ratio of the rotational speed of the molding drum is kept constant, and a rubber strip material having a stable predetermined shape is supplied to the tire molding drum.

  Thus, conventionally, a rubber strip material having a fixed shape is wound around a core drum to form a laminated molded member. Therefore, if the width of the rubber strip material is reduced, the desired shape of the laminated molded member can be accurately molded. However, the number of layers to be laminated (winding rotation speed) becomes excessive, and the production efficiency becomes extremely poor.

  On the other hand, if the width of the rubber strip material is wide, the number of layers to be laminated is small and the production efficiency is good, but the desired shape of the laminated molded member cannot be accurately formed (see FIG. 4).

  The present invention has been made in view of the above points, and its object is to provide a rubber strip lamination molding method capable of improving the production efficiency and accurately molding a desired shape of a laminated molding member. is there.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a rubber strip laminate in which a rubber strip material extruded from an extruder and formed by a roller die is wound while partially overlapping a rotating core drum to form a laminated molded member. In the molding method, the winding speed Vd of the rubber strip material of the core drum is set to a constant speed higher than the rotation speed Vr of the roller die, and the rotation speed Vr of the roller die is set according to the winding location where the laminated molding member is formed. It is a rubber strip lamination molding method to be changed.

According to the rubber strip lamination molding method of claim 1 , since the rotation speed of the roller die is changed according to the winding location where the laminated molding member is formed, the width of the rubber strip material is varied depending on the winding location of the lamination molding member. By controlling and winding to the optimum width, it is possible to improve the production efficiency with a small number of laminations and to accurately mold the desired shape of the laminated molded member.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
The present embodiment relates to a method of directly molding a tire constituent member by winding a rubber strip material around a core drum, and FIG. 1 shows a schematic perspective view of the molding apparatus 10.

  The rotating shaft 12 protrudes from the base 11, and a toroidal core drum 13 as a support is integrally provided on the rotating shaft 12, and the core drum 13 is rotated together with the rotating shaft 12 by the drum rotation motor provided on the base 11. .

An extruder 15 is disposed with the base 16 facing the core drum 13.
The extruder 15 forms the charged rubber material into a band shape from the die 16, extrudes it as a rubber strip material 1, and supplies it toward the core drum 13.
The supplied rubber strip material 1 is wound while being pressed onto the core drum 13 by the sticking roller 17.

  The extruder 15 itself can move in the direction of the rotation center axis (X direction) of the core drum 13 integrally with the sticking roller 17 and can also move in the direction perpendicular to the direction of the rotation center axis (Y direction). The extrusion direction can be changed by rotating in the θ direction about the axis, and the rubber strip material 1 can be supplied from the outer peripheral surface to the side surface of the toroidal core drum 13 and can be wound in a spiral manner.

  The drum rotation motor, the extrusion motor that rotates the screw of the extruder 15, and each movement motor that performs various movements of the extruder 15 are controlled by a control device 20 by a computer, and each control signal of the control device 20 is a drum rotation. The motor is output to the motor driver 21, the extrusion motor driver 22, and the moving motor driver 23, and each motor is driven and controlled by each driver.

Now, a case where one tread member 2 as a tire constituent member is laminated on the core drum 13 will be described.
The core drum 13 rotates at a winding speed Vd, which is a peripheral speed, and the extruder 15 is controlled by the control device 20 to perform extrusion at an extrusion speed Ve while moving mainly in the rotation center axis direction (X direction) of the core drum 13. The rubber strip material 1 is partially overlapped and wound spirally around mainly the outer peripheral surface of the core drum 13 (see FIG. 2).

  By controlling the moving speed of the extruder 15 relative to the winding speed Vd of the core drum 13 in the direction of the rotation center axis (X direction), the rubber strip materials 1 are partially overlapped, and the degree of overlap is also adjusted to be spiral. The cylindrical tread member 2 which is a laminated molding member is formed on the core drum 13 by winding.

  The control device 20 determines in advance a laminated pattern for obtaining a required tread cross-sectional shape indicated by a two-dot chain line in FIG. 3, and controls the rubber strip material 1 to be wound according to the laminated pattern.

  Here, in the present embodiment, the speed ratio Vd / Ve of the winding speed Vd of the core drum 13 to the extrusion speed Ve of the extruder 15 is changed and controlled according to the winding location where the tread member 2 is to be formed. Yes.

Actually, the winding speed Vd of the core drum 13 is changed while keeping the extrusion speed Ve of the extruder 15 constant.
Since the extrusion speed Ve of the extruder 15 is constant, the extruder 15 can be driven stably, and the winding speed Vd of the core drum 13 is changed, so that the control according to the winding location is possible. Easy to do.

Note that the extrusion speed Ve may be changed while keeping the winding speed Vd constant, or the speed ratio Vd / Ve may be controlled by changing both in some cases.
In any case, the speed ratio Vd / Ve is controlled to always show a value of 1 or more.

  When the speed ratio Vd / Ve is large, the rubber strip material 1 is attached to the core drum 13 with a large degree of extension between the extruder 15 and the sticking roller 17 and the speed ratio Vd / Ve is conversely reduced. When it is small, the rubber strip material 1 is stuck to the core drum 13 while maintaining a small degree of expansion between the extruder 15 and the sticking roller 17.

As shown by a two-dot chain line in FIG. 3, the cross-sectional shape of the tread member 2 has a flat central portion, but the left and right side edge portions are special shapes and are difficult to form.
In the present embodiment, a rubber strip material having a narrow width by increasing the winding speed Vd of the core drum 13 (increasing the speed ratio Vd / Ve) at the stage of winding to form the left and right side edges of the tread member 2. By winding and laminating 1 around the core drum 13 while gradually increasing the width, the required side edge shape of the tread member 2 can be accurately formed as shown in FIG.

  At the stage where one side edge portion of the tread member 2 is formed and enters the flat portion, the rubber strip material 1 becomes wide when the winding speed Vd of the core drum 13 is low (speed ratio Vd / Ve is small). Is wound around the core drum 13 while maintaining a constant width, and the central flat portion is laminated.

  When the central flat portion of the tread member 2 is finished and enters the other side edge portion, the winding speed Vd of the core drum 13 is gradually increased (the speed ratio Vd / Ve is increased) and the width becomes narrower. By winding and laminating the rubber strip material 1 around the core drum 13, the other required side edge shape of the tread member 2 can be accurately formed.

  If the narrowest rubber strip material 1 is used in all winding stages, the required tread cross-sectional shape can be formed with the same accuracy, but the number of laminated rubber strip materials 1 increases and the production efficiency increases. Although it becomes worse, as in the present embodiment, the speed ratio Vd / Ve is changed in accordance with the winding location where the tread member 2 is to be formed, and the width of the rubber strip material 1 is adjusted, thereby reducing the number of laminated layers. The production efficiency can be improved and the desired shape of the tread member 2 can be formed with high accuracy, and the appearance of the product tire can be improved with improved appearance.

  When the wide rubber strip material 1 is used in all winding stages, the production efficiency is improved. However, as shown in FIG. 4, a desired cross-sectional shape can be obtained with high accuracy at the side edge of the tread member. Therefore, the tread surface becomes rough, cracks occur, and the end of the rubber strip material 1 protrudes, resulting in poor appearance of the product and reduced merchantability.

  Here, the partial cross-sectional views in the course of molding the tread member in FIGS. 3 and 4 show the rubber strip material exaggerated for easy understanding.

  In the present embodiment, the tread member 2 is molded. However, other tire constituent members such as an inner liner and a side wall, and various rubber ring members can be molded with high accuracy and efficiency.

Next, an embodiment using an extruder in which a rubber strip material is formed by a roller die will be described with reference to FIG.
A roller die 51 is provided in the vicinity of the extrusion outlet of the extruder 50, and the rubber strip material 1 having a required shape is formed by the roller die 51.

  The core drum 55 is positioned in front of the roller die 51, and the rubber strip material 1 supplied from the roller die 51 is pressed against the core drum 55 rotated by the sticking roller 52 and wound spirally.

  Here, when the rotational speed Vr of the roller die 51 is changed, the degree of expansion of the rubber strip material 1 changes and the rubber strip material 1 is deformed in relation to the winding speed Vd of the core drum 13 (a constant speed faster than Vr). To do.

  When the rotational speed Vr of the roller die 51 is increased, the rubber strip material 1 is formed to be wide with a small degree of expansion, and when the rotational speed Vr is decelerated, the rubber strip material 1 is formed to have a large degree of expansion and a narrow width.

  Therefore, by changing the rotational speed Vr of the roller die 51 and adjusting the width of the rubber strip material 1 according to the winding location where the laminated molded member is to be formed, the tread member 2 is improved in production efficiency with a small number of laminated layers. The desired shape can be formed with high accuracy, and the appearance of the product tire can be improved and the merchantability of the product tire can be improved.

It is a schematic perspective view of the shaping | molding apparatus which concerns on this Embodiment. It is the principal part side view. It is a fragmentary sectional view in the middle of fabrication of a tread member. It is a fragmentary sectional view in the middle of molding of a tread member by the conventional rubber strip lamination molding method. It is a principal part side view of the shaping | molding apparatus which concerns on another embodiment.

Explanation of symbols

1 ... rubber strip material, 2 ... tread member,
10 ... Molding device, 11 ... Base, 12 ... Rotating shaft, 13 ... Core drum, 15 ... Extruder, 16 ... Base, 17 ... Paste roller,
20 ... Control device, 21 ... Drum rotation motor driver, 22 ... Extrusion motor driver, 23 ... Moving motor driver,
50 ... Extruder, 51 ... Roller die, 52 ... Sticking roller, 55 ... Core drum.

Claims (1)

In a rubber strip lamination molding method in which a rubber strip material extruded from an extruder and formed by a roller die is wound while partially overlapping a rotating core drum to form a laminated molding member.
The winding speed Vd of the rubber strip material of the core drum is set to a constant speed higher than the rotational speed Vr of the roller die,
A method of laminating and forming a rubber strip, wherein the rotational speed Vr of the roller die is changed according to a winding location where the laminated molding member is formed.

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