JP2010228343A - Ring member forming method and ring member forming apparatus - Google Patents

Abstract

When forming an annular member having an annular bead core and a bead filler disposed on the outer side in the radial direction of the bead core, deformation of the annular member due to an inner / outer peripheral difference or its own weight can be suppressed. An annular member forming method and an annular member forming apparatus are provided.
An annular member molding method for molding an annular member 10 having an annular bead core 1a and a bead filler 1b disposed on the outside in the radial direction of the bead core 1a. The bead filler 1b is extruded on the tray 40 while the tray 40 is rotated together with the mold 21 while the tray placing process of placing the tray 40 thereon, the bead core placing process of placing the bead core 1a on the tray 40, and the mold 21. A bead filler molding step, and a demolding step of removing the tray 40 from the mold 21 and demolding the annular member 10 in which the bead core 1a and the bead filler 1b are integrated from the tray 40.
[Selection] Figure 5

Description

  The present invention relates to an annular member forming method and an annular member forming apparatus for forming an annular member having an annular bead core and a bead filler disposed on the outside in the radial direction of the bead core.

  As shown in FIG. 8, the tire is configured by combining various rubber members such as a sidewall rubber 2, a tread rubber 3, a carcass ply 4, and an inner liner rubber 5. The bead member 10 is disposed in each of the pair of bead portions 1, and the end portion in the width direction of the carcass ply 4 is wound back so as to sandwich the bead portion 10. As shown in FIG. 9, the bead member 10 includes an annular bead filler 1 b made of hard rubber having a triangular cross section, and a bead core 1 a made of a convergent body such as a rubber-coated steel wire.

  For example, as shown in FIG. 10, the bead member 10 supplies the bead filler 1b extruded in a band shape by the extruder 81 via the base 82 to the bead core 1a formed in an annular shape in advance, and is placed on the inner periphery of the bead filler 1b. It is manufactured by bonding the bead core 1a (see Patent Document 1 below). The bead core 1a is supported so as to be rotatable in the r direction, and the rotation speed is controlled so as to correspond to the extrusion speed of the bead filler 1b. The bead filler 1b is cut into a predetermined length, and then the ends thereof are bonded together to form an annular shape.

  However, when the belt-shaped bead filler 1b is formed into an annular shape as in the following cited document 1, the tensile stress in the circumferential direction acts on the outer peripheral portion of the bead filler 1b due to the inner and outer peripheral differences. 1b may be bent and deformed, or the bead filler 1b may be deformed in a direction opposite to the bead core 1a (X direction), thereby hindering bonding between end portions.

  Therefore, in order to suppress non-uniformity of the bead filler elongation, in the following cited document 2, an annular reference member (corresponding to a bead core) is disposed on a rotating disk-shaped plate, and the plate is heated. In this state, the rubber-like elastic material having a reduced viscosity is supplied to the outer peripheral surface of the annular reference member while rotating at a constant rotational speed, and the rubber-like elastic material is annularly formed by a heated die. An annular member (corresponding to a bead filler) is formed by rotating the plate while pressing the reference member.

JP-A-6-297603 JP 2002-187218 A

  However, even in the molding method of Cited Document 2, when a rubber-like elastic material extruded in a string shape or a belt shape from an extruder is attached to an annular bead core to form a bead filler, the bead filler is caused by the tension generated by the difference between the inner and outer circumferences. There is a risk of bending and deformation.

  Further, in the molding method of Cited Document 2, since a bead filler is molded by pressing a rubber-like elastic material on a flat plate with a die, the shape of the bead filler collapses when trying to mold a non-planar bead filler. End up. Furthermore, if you try to remove the bead member from the plate immediately after molding, if the rubber temperature is high, the rubber will adhere to the plate and the shape of the bead filler will collapse, or if you remove the bead member from the plate and stand the bead member by its own weight May be bent and the shape may collapse.

  The present invention has been made in view of the above situation, and when forming an annular member having an annular bead core and a bead filler disposed on the radially outer side of the bead core, An annular member forming method and an annular member forming apparatus capable of suppressing deformation of an annular member due to its own weight.

In order to solve the above problems, an annular member molding method according to the present invention is:
An annular member molding method for molding an annular member having an annular bead core and a bead filler disposed radially outside the bead core,
A tray placing step of placing the tray on a rotatable mold;
A bead core disposing step of disposing a bead core on the tray;
While rotating the tray together with the mold, a bead filler molding step of extruding a bead filler on the tray;
A demolding step of removing the tray from the mold, and demolding the annular member in which the bead core and the bead filler are integrated, from the tray.

  The operation and effect of the annular member forming method having such a configuration will be described. A tray is placed on a rotatable mold, and an annular bead core is placed on the tray. Next, the tray is rotated by rotating the mold, and the bead filler is extruded on the tray. At this time, the bead filler is molded on the radially outer side of the bead core arranged on the tray. When the molding of the bead filler is finished, the tray is removed from the mold, and the annular member in which the bead core and the bead filler are integrated is removed from the tray.

  According to this configuration, since the bead filler is extruded on the tray, the difference between the inner and outer peripheries is compared to the method of supplying the bead filler extruded in a strip shape to the outer periphery of the bead core and directly bonding it as in the above cited reference 1. It is possible to suppress the deformation caused by. Further, in the molding method of the above cited reference 2, since the annular member is formed directly on the mold, in order to continuously form the next annular member, the molded annular member is used. Must be removed from the mold immediately. On the other hand, according to the configuration of the present invention, since the annular member is formed on the tray placed on the mold, it is not necessary to immediately remove the annular member from the tray. By removing the tray together with the annular member from the mold after molding and placing the annular member on the tray as it is, the stress (tension) generated by the difference between the inner and outer circumferences is alleviated, and deformation of the bead filler is suppressed. In addition, by placing an annular member on the tray after molding, the temperature of the rubber is lowered and the hardness is increased, so that even if the mold is removed from the tray, the bead filler can be prevented from being bent due to its own weight and deformed. it can. As a result, according to the present invention, when forming an annular member having an annular bead core and a bead filler disposed on the outer side in the radial direction of the bead core, the annular member is deformed due to an inner / outer peripheral difference or its own weight. Can be suppressed.

  In the annular member molding method according to the present invention, it is preferable to extrude the bead filler by supplying rubber extruded from an extruder directly onto the tray.

  The rubber is extruded from the extruder and supplied directly to the tray, and the bead filler is molded, so the rubber temperature is high and the viscosity is low, and even if an annular bead filler is molded, the tension generated by the difference between the inner and outer circumferences There are few. As a result, when an annular member having an annular bead core and a bead filler disposed on the outer side in the radial direction of the bead core is formed, deformation of the annular member due to the difference between the inner and outer circumferences can be suppressed.

  Moreover, the annular member molding method according to the present invention preferably includes a cooling step of cooling the annular member on the tray by blowing air onto the annular member.

  According to this configuration, air is blown and cooled on the annular member in which the bead core and the bead filler are integrated, so that the rubber is cooled to increase the viscosity and prevent dripping due to low viscosity.

Further, in the bead filler molding step of extruding a bead filler by sticking rubber extruded from an extruder on the tray while rotating the tray at a constant speed,
Bring the extruder close to the tray and start sticking the extruded rubber,
After starting rubber sticking, the rubber extrusion speed is gradually accelerated to a certain speed, and the extruder is gradually separated from the tray to a certain distance,
It is preferable that the rubber extrusion speed is gradually reduced from a constant speed immediately before the rubber application is completed.

  According to this structure, a bead filler is shape | molded by sticking the rubber extruded from the extruder on the tray which rotates at a fixed speed. In this bead filler molding process, the extruder is brought close to the tray to start sticking the extruded rubber, and after the rubber sticking starts, the rubber extrusion speed is gradually accelerated to a constant speed and the extruder By gradually separating the tape from the tray to a certain distance, the thickness of the rubber to be attached to the tray gradually increases. The thickness of the rubber to be attached to becomes gradually thinner. As a result, when joining the pasting start position and the pasting end position, there is no step at the joint by overlapping the part where the rubber thickness gradually increases and the part where the rubber thickness gradually decreases. . In addition, after starting the rubber sticking, the rubber extrusion speed is gradually accelerated, and the extruder is gradually separated from the tray to a certain distance, so that even if the rubber thickness gradually increases, It can prevent that the rubber affixed on the tray contacts.

In order to solve the above problems, an annular member forming apparatus according to the present invention includes:
An annular member forming apparatus for forming an annular member having an annular bead core and a bead filler disposed on the radially outer side of the bead core,
A rotatable mold,
A tray placed on the mold and capable of placing a bead core;
An extruder for extruding rubber onto the tray to mold a bead filler.

  The operation and effect of the annular member forming apparatus having such a configuration is as described above, and when forming an annular member having an annular bead core and a bead filler disposed radially outside the bead core. Furthermore, the deformation of the annular member due to the difference between the inner and outer circumferences and the own weight can be suppressed.

External perspective view showing a schematic configuration of a device for forming an annular member Side view of molding equipment External perspective view of tray Schematic configuration diagram showing the entire molding equipment for annular members Explanatory drawing for demonstrating the formation process of an annular member Explanatory drawing for demonstrating a mode that an annular member is demolded from a tray. Explanatory drawing for demonstrating the extrusion molding process of a bead filler Sectional drawing which shows an example of a pneumatic tire Perspective view showing a partially broken bead member The figure which shows a mode that an annular member is manufactured by the conventional method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, as shown in FIG. 9, the annular member 10 is an example of a bead member having an annular bead core 1a and a bead filler 1b disposed on the radially outer side of the bead core 1a. The cross section of the bead filler 1b shows an example in which the outer peripheral portion is a triangular shape.

  FIG. 1 is an external perspective view showing a schematic configuration of an annular member forming apparatus according to the present invention. FIG. 2 is a side view of the molding apparatus.

  The molding apparatus includes a rotary table 20 having a mold 21 attached to the upper surface and an extruder 30.

  The rotary table 20 can rotate around a rotary shaft 20a as indicated by an arrow in the figure. The rotary table 20 can be driven to rotate by a motor (not shown), and the rotational speed of the rotary table 20 can be freely controlled by controlling the rotational speed of the motor. In addition, the rotation direction of the turntable 20 is not restricted to the direction shown in the figure.

  The mold 21 is fixed to the upper surface of the rotary table 20 and can be rotated simultaneously by the rotation of the rotary table 20. That is, the rotational speed of the mold 21 can be freely controlled in the same manner as the rotational speed of the rotary table 20.

  The mold 21 has a substantially disk shape. The upper surface of the mold 21 includes a convex portion 22, a concave portion 23, and a peripheral edge portion 24 in order from the center portion.

  At the center of the convex portion 22, a further protruding portion 22 a is provided. A pin 25 is erected on the periphery of the convex portion 22. The pin 25 plays a role of positioning the tray 40, which will be described later, and rotating.

  The recess 23 is provided in an annular shape on the upper surface of the mold 21. As shown in FIG. 2, the recess 23 includes a horizontal portion 23a that is substantially horizontal and a slope portion 23b that is inclined with respect to the horizontal portion 23a.

  A pin 26 is erected on the peripheral edge 24. Similar to the pin 25, the pin 26 also serves to position and rotate the tray 40 described later.

  The extruder 30 can be moved in the horizontal direction and the vertical direction as shown by arrows in the drawing by a driving means (not shown). The extruder 30 can move closer to or away from the mold 21 by moving in the horizontal direction. Further, the extruder 30 can move closer to or away from the upper surface of the mold 21 by moving in the vertical direction.

  The extruder 30 has a known configuration and will not be described in detail, but mainly, a hopper into which a rubber material is charged, a screw that feeds the rubber material forward while applying heat to the rubber material, and a cylindrical barrel that contains the screw And a drive device for driving the screw. The drive and rotation amount of the screw are controlled by a control device. Further, the extruder 30 is provided with a constant capacity pump, and the extrusion speed of the rubber can be controlled.

  The extruder 30 includes a base 31 at the tip. Rubber is extruded from the opening formed in the front surface of the base 31. The opening of the base 31 has a shape corresponding to the cross-sectional shape of the bead filler 1b. However, the opening of the base 31 may be a simple rectangular shape, for example, and the extruded rubber having a rectangular cross-sectional shape may be pressed against the tray 40 to be molded into a desired cross-sectional shape of the bead filler 1b.

  FIG. 3 shows an external perspective view of the tray 40. The tray 40 has a thin plate shape that covers the upper surface of the mold 21. For the tray 40, for example, a material such as polypropylene can be used.

  The tray 40 includes a convex portion cover portion 41 corresponding to the shape of the convex portion 22 of the mold. A through-hole is provided at the center of the convex cover portion 41 so that the protruding portion 22a of the mold can pass therethrough. The convex cover 41 is provided with a pin hole 44 into which the pin 25 of the mold 21 can be inserted.

  Further, the tray 40 includes a member forming portion 42 on the outer peripheral side of the convex portion cover portion 41. The member forming portion 42 is a portion where the annular member 10 is formed, and has an arbitrary annular member 10 shape to be formed. The member molding part 42 includes a bead core arrangement part 42a and a bead filler molding part 42b. The bead core arrangement portion 42 a has a shape corresponding to the horizontal portion 23 a of the mold 21 when the tray 40 is placed on the upper surface of the mold 21. Further, the bead filler molding portion 42 b has a shape corresponding to the slope portion 23 b of the mold 21 when the tray 40 is placed on the upper surface of the mold 21.

  Further, the tray 40 includes a peripheral cover portion 43 on the outer peripheral side of the member forming portion 42. The peripheral cover portion 43 has a shape corresponding to the peripheral portion 24 of the mold 21 when the tray 40 is placed on the upper surface of the mold 21. Further, the peripheral cover portion 43 is provided with a pin hole 45 into which the pin 26 of the mold 21 can be inserted. Furthermore, a hook hole 46 is provided in the outer edge portion of the peripheral cover portion 43, and the tray 40 can be suspended using this hook hole 46.

<Method of forming annular member>
An annular member forming method according to the present invention will be described with reference to the drawings. FIG. 4 is a schematic configuration diagram showing the entire molding equipment for the annular member 10. A rail 50 is disposed above the rotary table 20, the mold 21, and the extruder 30. A plurality of hooks 51 are suspended on the rail 50. Each hook 51 can move horizontally along the rail 50 while the tray 40 is suspended. Each hook 51 can also be moved up and down. By hanging the tray 40 and moving it up and down, the tray 40 can be placed on the mold 21 or the mold 21 as shown in the figure. Can be pulled away from. A blower 52 is disposed on the side of the rail 50 so that air can be blown onto the annular member 10.

  FIG. 5 is an explanatory view for explaining a molding process of the annular member 10, and is a view of the annular member 10 as viewed from the side.

  First, the tray 40 is placed on the mold 21 as shown in FIG. The tray 40 is placed from above the mold 21 with the hook 51 placed in the hook hole 46 and suspended. At this time, the tray 40 is positioned by inserting the pins 25 and 26 of the mold 21 into the pin holes 44 and 45 of the tray. After placing the tray 40 on the mold 21, the hook 51 is removed from the hook hole 46.

  Next, as shown in FIG. 5B, the bead core 1 a is placed on the bead core placement portion 42 a of the tray 40. The bead core 1a is an annular member made of a converging body such as a rubber-coated steel wire as shown in FIG. After placing the bead core 1a in the bead core placement portion 42a, the extruder 30 is moved toward the center of the tray 40, and the base 31 is placed above the bead filler molding portion 42b.

  Next, as shown in FIG. 5C, the extruder 30 is lowered to bring the die 31 and the tray 40 close to each other. And the bead filler 1b which has a cross-sectional shape corresponding to the shape of the bead filler molding part 42b is shape | molded by rotating the turntable 20, pushing rubber out from opening of the nozzle | cap | die 31. At this time, the shape may be adjusted by pressing the upper surface of the rubber extruded from the base 31 with the rotating roller 32 as shown in the figure. The rubber is continuously pushed out one turn on the tray 40, and an annular bead filler 1b is molded. Moreover, the bead core 1a and the bead filler 1b are integrated by this process, and the annular member 10 is shape | molded.

  When the annular member 10 is formed, the extruder 30 is moved up and horizontally as shown in FIG. Then, the hook 51 is hooked on the hook hole 46 of the tray 40, and the tray 40 is pulled upward to be separated from the mold 21. Thus, since the molded annular member 10 can be separated from the mold 21 while being placed on the tray 40, the next tray 40 is immediately placed on the mold 21 and Since the annular member 10 can be molded in the same process, the molding cycle is not lost. Further, the tray 40 also serves as a separator that prevents the annular members 10 after the molding from sticking to each other, and the molding operation is easy.

  The tray 40 separated from the mold 21 and suspended from the hook 51 is moved in the horizontal direction, and the annular member 10 can be cooled by blowing air with the blower 52 as shown in FIG. By cooling the annular member 10, the rubber is cooled to increase the viscosity, and the dripping of the rubber due to the low viscosity can be prevented.

  As shown in FIG. 6A, the cooled annular member 10 on the tray 40 is easily bent from the member forming portion 42 of the tray 40 by bending the entire tray 40 as shown in FIG. Can be demolded.

<Bead filler extrusion molding method>
The extrusion molding method of the bead filler 1b has been briefly described above, but will be described in more detail here. FIG. 7 shows a process of attaching the rubber R extruded from the extruder 30 onto the tray 40.

  As shown in FIG. 7A, the die 31 of the extruder 30 is lowered to the vicinity of the surface of the tray 40 and brought into proximity, and the rubber R starts to be extruded. Thereby, the rubber R extruded from the extruder 30 is started to be stuck on the tray. At this time, the tray 40 has not yet rotated.

  Next, as shown in FIGS. 7B and 7C, the rotation of the tray 40 is started, and at the same time, the extrusion speed of the rubber R from the base 31 is gradually accelerated. At the same time as the rotation of the tray 40 starts, the base 31 starts to rise, and the base 31 is gradually separated from the tray 40. As a result, the thickness of the rubber R attached to the tray 40 gradually increases.

  After the thickness of the adhered rubber R reaches the desired thickness of the bead filler 1b, as shown in FIG. 7 (d), the base 31 is continuously raised and the extrusion speed is accelerated, and after the rubber R has reached the desired thickness. Stops the base 31 and keeps the extrusion speed constant. With the above operation, the rubber R sticking start position has an inclined surface as shown in the figure, and thereafter, the thickness of the rubber R becomes constant.

  When the base 31 approaches the sticking start position as shown in FIG. 7E while sticking the rubber R with a constant thickness, the extrusion speed is gradually reduced. As a result, as shown in FIG. 7 (f), the rubber R at the attachment end position also becomes an inclined surface so as to correspond to the inclined surface at the application start position, and the bead filler 1b having no step at the joining portion can be molded. it can.

DESCRIPTION OF SYMBOLS 1 Bead part 1a Bead core 1b Bead filler 10 Ring-shaped member 20 Rotary table 21 Mold 30 Extruder 31 Base 40 Tray 42 Member molding part 42a Bead core arrangement part 42b Bead filler molding part 52 Blower R Rubber

Claims (5)

An annular member molding method for molding an annular member having an annular bead core and a bead filler disposed radially outside the bead core,
A tray placing step of placing the tray on a rotatable mold;
A bead core disposing step of disposing a bead core on the tray;
While rotating the tray together with the mold, a bead filler molding step of extruding a bead filler on the tray;
An annular member forming method comprising: a mold removing step of removing the tray from the mold and removing the annular member in which the bead core and the bead filler are integrated from the tray.   The annular member molding method according to claim 1, wherein the bead filler is extruded by directly feeding rubber extruded from an extruder onto the tray.   The method for forming an annular member according to claim 1, further comprising a cooling step of cooling the annular member on the tray by blowing air onto the annular member. In the bead filler molding step of extruding a bead filler by sticking rubber extruded from an extruder on the tray while rotating the tray at a constant speed,
Bring the extruder close to the tray and start sticking the extruded rubber,
After starting rubber sticking, the rubber extrusion speed is gradually accelerated to a certain speed, and the extruder is gradually separated from the tray to a certain distance,
The method of forming an annular member according to any one of claims 1 to 3, wherein the rubber extrusion speed is gradually reduced from a constant speed immediately before completion of rubber sticking. An annular member forming apparatus for forming an annular member having an annular bead core and a bead filler disposed on the radially outer side of the bead core,
A rotatable mold,
A tray placed on the mold and capable of placing a bead core;
An annular member forming apparatus comprising: an extruder for extruding rubber onto the tray to form a bead filler.

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