JP2013006326A - Rigid core - Google Patents

Abstract

A rigid core is assembled and disassembled with high accuracy, stability and efficiency without using bolts.
A core body composed of a plurality of core segments divided in the tire circumferential direction, and a cylindrical shape that is inserted into a center hole of the core body to prevent the movement of each core segment inward in the radial direction. A pair of side plates disposed on both sides of the core body in the axial direction and preventing movement of each core segment in the axial direction by holding the core body between the inner side surfaces. With A first dovetail portion is formed on the outer peripheral surface of the core, and a second dovetail portion engaging with the first dovetail portion is formed on the inner peripheral surface of each core segment. The side plate on one side is fixed at one end of the core, and the side plate on the other side protrudes from a boss portion that can be screwed into an inner screw portion provided in the center hole of the core.
[Selection] Figure 1

Description

  The present invention relates to a rigid core capable of accurately and efficiently removing a rigid core from a lumen of a pneumatic tire and reassembling the removed rigid core.

  In recent years, in order to improve the formation accuracy of a pneumatic tire, a rigid core a having an outer shape corresponding to the tire inner surface shape of a vulcanized finished tire is used as shown in FIG. A tire constituent member such as an inner liner, a carcass ply, a belt ply, a sidewall rubber, and a tread rubber is sequentially pasted on a to form an unvulcanized tire t. And a method for vulcanizing and molding a pneumatic tire between a rigid core a that is an inner mold and a vulcanization mold b that is an outer mold has been proposed (for example, patents). Reference 1).

  In this rigid core a, a plurality of core bodies a1 are divided in the tire circumferential direction so as to be disassembled and removed from the lumen of the pneumatic tire after vulcanization molding, as shown in FIG. The core segment c is formed. Specifically, the first core segment c1 in which the dividing surfaces at both ends in the circumferential direction are inclined in the direction in which the circumferential width decreases toward the inner side in the radial direction, and the first core segment c1 are alternately arranged in the circumferential direction. And the split surfaces at both ends in the circumferential direction are inclined inward in the radial direction so as to increase in the circumferential width, and the radius is sequentially increased from the second core segment c2. The core body a1 can be disassembled and removed from the vulcanized tire by moving it one by one inward in the direction.

  Each core segment c is assembled into an annular shape by bolting the inner end in the radial direction to the core portion d1 of the frame d having an annular core portion d1. The frame d can be attached and detached from the opening f by opening one end of the core part d1.

  However, in such a structure, it is difficult to automatically remove and attach the bolt e, and since there are many bolt fixing portions, the workability is inferior, such as requiring a lot of labor for disassembling and assembling the rigid core a. Further, it is difficult to position each core segment c and to assemble the rigid core a with high accuracy and stability.

JP 2006-160236 A

  Therefore, an object of the present invention is to provide a rigid core that can be assembled and disassembled with high accuracy, stability and efficiency without using bolts, and can greatly contribute to the automation of the assembly and disassembly.

In order to solve the above-mentioned problem, the invention of claim 1 of the present application is a rigid core comprising an annular core body provided on the outer surface with a molding surface for molding a lumen surface of a pneumatic tire,
The core body comprising a plurality of core segments divided in the tire circumferential direction and movable inward in the radial direction;
A cylindrical core that is inserted into the center hole of the core body and prevents the core segments from moving inward in the radial direction;
A pair of side plates disposed on both sides of the core body in the axial direction, and holding the core body between the inner side surfaces to prevent movement of each core segment in the axial direction;
In addition, a first dovetail portion comprising one of a dovetail groove or an ant tenon extending in the axial direction is formed on the outer peripheral surface of the core, and extending in the axial direction on the inner peripheral surface of each core segment. A second dovetail portion formed of the other of an ant groove or an ant tenon engaged with the first ant joint portion is formed;
The end plate on one side of the core is fixed to the side plate on one side in the axial direction, and the side plate on the other side in the axial direction is screwed to the inner screw portion provided in the center hole of the core on the inner side surface of the side plate. By projecting a boss portion that can be inserted, the core portion is detachable from the other end portion of the core.

  According to a second aspect of the present invention, the core segment includes a first core segment in which split surfaces at both ends in the circumferential direction are inclined in a direction in which a circumferential width decreases toward the inner side in the radial direction, and the first core segment. The core segments are composed of second core segments that are alternately arranged in the circumferential direction and in which the dividing surfaces at both ends in the circumferential direction are inclined inwardly in the direction of increasing the circumferential width toward the inside in the radial direction. This makes it possible to move inward in the radial direction.

  According to a third aspect of the present invention, the side plates on one side and the other side in the axial direction include support shaft portions that protrude outward in the axial direction.

  According to a fourth aspect of the present invention, the support shaft portion is formed with a locking portion made of a key groove or a key-like protrusion for preventing rotation on an end surface thereof.

  As described above, the present invention includes a cylindrical core inserted in the core body and a pair of side plates disposed on both sides in the axial direction of the core body, and one end of the core. The part is fixed to the side plate on one side.

  A first dovetail portion extending in the axial direction is formed on the outer peripheral surface of the core, and a second dovetail portion extending in the axial direction is formed on the inner peripheral surface of each core segment. Is formed. Accordingly, the core segments can be sequentially arranged around the core while being guided by the first dovetail portion. At this time, since the first and second dovetail joints are engaged with each other, misalignment of the core segment can be prevented, and high-precision, stable and efficient assembly can be achieved.

  On the other side plate, a boss portion that can be screwed into the center hole of the core is projected. For this reason, the boss portion is screwed to hold the core body between the side plates and prevent the core segments from moving in the axial direction. Therefore, the engagement between the first and second dovetail joints, the movement of the core segment to the inside in the radial direction by the core, and the axial direction of the core segment by the clamping between the side plates By preventing the movement, the assembled core segments can be fixed, and the core body can be maintained with high accuracy. Moreover, since the rigid core is fixed with only one screw connection without using bolts, the assembly work efficiency and the disassembly work efficiency can be greatly increased, and the assembly and disassembly can be automated greatly. Can contribute.

It is sectional drawing which shows one Example of the rigid core of this invention. It is a top view which shows a core main body with a core. It is a disassembled perspective view of a rigid core. It is an enlarged view which shows the engagement state of the 1st, 2nd dovetail part. It is sectional drawing explaining a connection means. (A)-(C) are sectional drawings explaining the order which disassembles a rigid core. It is sectional drawing explaining taking out from the tire of a core main body, and an assembly. It is a top view explaining taking out from a tire of a core main part, and assembling. It is sectional drawing explaining the attachment to the core of the other side plate. (A) is sectional drawing which shows the formation method of the pneumatic tire which used the rigid core, (B) is a side view of the axial direction of a rigid core.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, the rigid core 1 of the present embodiment includes an annular core body 3 having a molding surface 2 for molding a lumen surface Ts of a pneumatic tire T on the outer surface. Then, on the molding surface 2 of the core body 3, tire constituent members such as an inner liner, a carcass ply, a belt ply, a sidewall rubber, and a tread rubber are sequentially attached to form an unvulcanized tire. The pneumatic tire T is vulcanized and molded by putting the unvulcanized tire together with the rigid core 1 into a vulcanization mold. FIG. 1 shows a state in which the rigid core 1 is taken out from the vulcanization mold together with the vulcanized pneumatic tire T and transferred onto the holding shaft 4.

  The rigid core 1 includes a pair of core bodies 3, a cylindrical core 5 that is inserted into a center hole 3 </ b> H of the core body 3, and a pair of core bodies 3 that are disposed on both sides in the axial direction. Side plates 6L and 6U are provided.

  The core body 3 has a tapered surface 7 that is inclined radially outwardly inward in the axial direction and radially outward of the main portion 3A having the molding surface 2, and bulges outward in the axial direction. A concave portion 8 that is concentric with the core body 3 is formed inside the core body 3. In this example, a case where steam, which is a heat medium for vulcanization heating, is supplied into the recess 8 through a flow path (not shown) provided in the core 5 is shown. A heat source for vulcanization heating can be accommodated in the recess 8. The recess 8 is also used as a hook when the core body 3 is disassembled and hung from the tire T and taken out.

  As shown in FIGS. 2 and 3, the core body 3 is composed of a plurality of core segments 9 divided in the tire circumferential direction. The core segment 9 has divided surfaces 9S at both ends in the circumferential direction. The first core segments 9A inclined in the direction of decreasing the circumferential width toward the inside in the radial direction and the first core segments 9A are alternately arranged in the circumferential direction, and divided at both ends in the circumferential direction. The surface 9S is composed of a second core segment 9B that is inclined in the direction in which the circumferential width increases inward in the radial direction. As a result, the core segment 9 can move the second core segment 9B radially inward, and accordingly, the first core segment 9A can also be sequentially moved radially inward. In the core body 3, as shown in FIGS. 7 and 8, the core body 3 can be sequentially moved from the second core segment 9B one by one inward in the radial direction, and sequentially taken out from the lumen TH of the tire T.

  Next, the core 5 has a cylindrical shape, and is inserted into the center hole 3H of the core body 3 to prevent the core segments 9 from moving inward in the radial direction. An end portion on one side of the core 5 in the axial direction is fixed to an inner surface of the side plate 6L on the one side in the axial direction. In this example, the case where the side plate 6L and the core 5 are fixed using a bolt 10 (shown in FIG. 1) is shown. However, when the rigid core 1 is disassembled and taken out from the tire T, it is not necessary to disassemble the side plate 6L and the core 5 on the one side. Therefore, this bolt fixing is performed by disassembling and assembling the rigid core. It has no effect on it. Therefore, the side plate 6L and the core 5 can be fixed by, for example, welding.

  The one side plate 6L includes a side plate main body 11 having a disc-shaped substrate portion 11A and a flange portion 11B provided on the outer peripheral edge of the substrate plate 11A and in contact with the tapered surface 7 of the core main body 3. A support shaft portion 12 that protrudes outward in the axial direction is provided concentrically on the outer surface of the substrate portion 11A. The flange portion 11B has the same inclination as the tapered surface 7, thereby allowing the side plate 6L and the core body 3 to be concentrically aligned, and between the flange portion 11B and the core 5, the intermediate portion The bulging portion 3B of the child main body 3 can be sandwiched and held.

  The core 5 has an inner screw portion 13 on the other side in the axial direction of the center hole 5H, and a dovetail groove 14 or an ant tenon 15 extending continuously in the axial direction on the outer peripheral surface of the core 5. The 1st dovetail part 16 which consists of one of these is formed. Further, on the inner peripheral surface of each core segment 9, a second dovetail portion 17 comprising the other of the dovetail groove 14 or the dovetail tenon 15 extending in the axial direction and engaging with the first dovetail portion 16. Is formed. In this example, the case where the dovetail groove 14 is formed as the first dovetail joint 16 and the ant tenon 15 is formed as the second dovetail joint 17 is shown, but conversely the first dovetail joint 16 The ant tenon 15 may be formed, and the ant groove 14 may be formed as the second ant joint 17. As shown in FIG. 4, the dovetail groove 14 and the ant tenon 15 have a substantially trapezoidal cross section in which both side surfaces are inclined in the direction of increasing the width toward the groove bottom and tenon tip, The other is engaged with each other so as to be relatively movable only in the axial direction.

  Next, the side plate 6U on the other side in the axial direction is a side plate body 20 having a disc-shaped substrate portion 20A and a flange portion 20B that is provided on the outer peripheral edge of the plate and contacts the tapered surface 7 of the core body 3. And a support shaft portion 21 that protrudes outward in the axial direction is provided concentrically on the outer surface of the substrate portion 20A. In this example, the substrate portion 20A and the support shaft portion 21 are formed in the same configuration as the substrate portion 11A and the support shaft portion 12 in the side plate 6L on one side in the axial direction.

  A boss portion 22 that can be screwed into an inner screw portion 13 provided in the center hole 5H of the core 5 is provided concentrically on the inner side surface of the substrate portion 20A. Therefore, the other side plate 6U can be detachably attached to the core 5 by the boss portion 22 and the inner screw portion 13. Further, at the time of attachment, like the side plate 6L, the flange portion 20B aligns the side plate 6U and the core body 3 concentrically, and between the flange portion 20B and the core 5, the core body 3 The bulging portion 3B can be sandwiched and held.

  In this example, a motor-driven rotating shaft 23 is connected via a connecting means 24 to the support shaft portion 21 of the other side plate 6U in order to attach and detach the other side plate 6U. Note that the support shaft portion 12 of the one side plate 6L and the holding shaft 4 are also connected via a connecting means 24 in this example. Hereinafter, the holding shaft 4 and the rotating shaft 23 are collectively referred to as a connecting shaft 25.

  The connecting means 24 has a ball lock mechanism in this example. Specifically, as shown in FIG. 5, the connecting means 24 is a connecting hole portion that is concentrically recessed at each outer end portion of the support shaft portions 12 and 21, and is provided with a circumferential groove 26A on the inner peripheral surface. 26, a connecting cylinder part 27 that is concentrically protruded from the outer end of the connecting shaft 25 and inserted into the connecting hole part 26, and a ball lock that locks between the connecting hole part 26 and the connecting cylinder part 27 Means 28 are provided.

  The ball lock means 28 includes a rigid ball 30 that is dispersedly arranged in the circumferential direction in the connecting cylinder portion 27 and that is held in a plurality of through holes 29 penetrating inward and outward in the radial direction, and a cylinder chamber 31 provided in the connecting shaft 25. A piston piece 33 that is housed in the cylinder chamber 31 and can move inward and outward in the axial direction in the cylinder chamber 31 by supplying and discharging compressed air to and from the cylinder chamber 31, and a central hole 27 </ b> H of the connecting cylinder portion 27. And a plunger 34 connected to the piston piece 33 so as to move integrally therewith.

  The plunger 34 can move outward in the axial direction in the center hole 27H of the connecting cylinder portion 27 by the piston piece 33. As a result of this movement, the outer peripheral surface of the plunger 34 abuts on each of the rigid balls 30 and pushes it up radially outward, and the rigid balls 30 can be pressed against the circumferential groove 26A and locked. The plunger 34 can be moved axially inward in the center hole 27H of the connecting cylinder portion 27 by the piston piece 33, thereby releasing the push-up of the rigid ball 30 outward in the radial direction. The lock between the part 26 and the connecting cylinder part 27 is released. The outer peripheral surface of the plunger 34 has a cone surface that tapers outward in the axial direction.

  Further, a locking portion 36 (shown in FIG. 3) made of one of a key groove for preventing rotation or a key-like protrusion is formed on the outer end surfaces of the support shaft portions 12 and 21, and the outside of the connection shaft 25. On the end surface, an engaging portion (not shown) is formed which is the other of the key groove or the key-like protrusion and engages with the locking portion 36.

Next, taking out from the pneumatic tire T and reassembly of the rigid core 1 of the present embodiment will be described.
FIG. 1 shows a state where the rigid core 1 with the pneumatic tire taken out from the vulcanization mold is transferred onto the holding shaft 4 as described above. Then, the rotary shaft 23 is lowered from above, and as shown in FIGS. 6A and 6B, the rotary shaft 23 and the support shaft portion 21 of the side plate 6U located therebelow are connected to the connecting means 24. Connect with one touch. Thereafter, the side plate 6U on one side can be removed from the rigid core 1 by rotating the rotary shaft 23. The removed side plate 6U is transferred to another place together with the rotary shaft 23 while being held by the connecting means 24.

  The annular core body receiver 40 rises from below and supports the core body 3 from below. Then, as shown in FIG. 6C, the holding shaft 4 is lowered together with the other side plate 6L. . As a result, the side plate 6L and the core 5 are integrally removed from the rigid core 1. The removed side plate 6L and the core 5 are transferred to the assembly place K (shown in FIG. 7) together with the holding shaft 4 while being held by the connecting means 24.

  Thereafter, as shown in FIGS. 7 and 8, the core segments 9 are taken out one by one from the core body 3 held on the core body receiver 40 using, for example, a holding jig 41 attached to the robot arm. The taken-out core segment 9 is transferred to the assembly place K and is sequentially attached around the core 5. In this example, the holding jig 41 has a hook shape, and is hooked on the recess 8 to move each core segment 9 inward in the radial direction, and then the core segment 9 is lifted and transferred to the assembly location K. To do. The core segments 9 are taken out and reassembled at the assembly location K as described above, one by one from the second core segment 9B, and all the second core segments 9B are taken out. Thereafter, the first core segments 9A are taken out one by one.

  After all the first and second core segments 9A and 9B are mounted around the core 5, as shown in FIG. 9, the rotating shaft 23 holding the side plate 6U is placed on the core 5. By lowering and rotating, the boss portion 22 of the side plate 6U can be screwed into the core 5 and the rigid core 1 can be reassembled.

  Here, since the first and second dovetail portions 16 and 17 are formed in the core 5 and each core segment 9, the core segments 9 are guided by the first dovetail portion 16. However, it can be sequentially arranged around the core. In addition, since the first and second dovetail joint portions 16 and 17 are engaged with each other, positional displacement of the core segment 9 can be prevented and high-precision and stable assembly can be achieved.

  Further, the other side plate 6U is provided with a boss portion 22 that can be screwed to the core 5, so that the core body 3 is sandwiched between the side plates 6L and 6U by the screwing of the boss portion 22. Thus, the movement of each core segment 9 in the axial direction can be prevented. Accordingly, the engagement between the first and second dovetail joint portions 16 and 17, the prevention of the movement of the core segment 9 in the radial direction by the core 5, and the sandwiching between the side plates 6 </ b> L and 6 </ b> U. By preventing movement of the core segment 9 in the axial direction, the assembled core segments 9 and 9 can be fixed, and the core body 3 can be maintained with high accuracy. Moreover, since the rigid core 1 is fixed by only one screw connection without using bolts, the assembly work efficiency and the disassembly work efficiency can be greatly increased, and the assembly and disassembly can be automated. can do.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

DESCRIPTION OF SYMBOLS 1 Rigid core 2 Molding surface 3 Core main body 3H Center hole 5 Core 5H Center holes 6L, 6U Side plate 9 Core segment 9A First core segment 9B Second core segment 9S Dividing surface 13 Internal screw part 14 Ant Groove 15 Ant tenon 16 First dovetail portion 17 Second dovetail portion 12 Support shaft portion 21 Support shaft portion 22 Boss portion 36 Locking portion T Pneumatic tire Ts Lumen surface

Claims (4)

A rigid core comprising an annular core body provided on the outer surface with a molding surface for molding a lumen surface of a pneumatic tire,
The core body comprising a plurality of core segments divided in the tire circumferential direction and movable inward in the radial direction;
A cylindrical core that is inserted into the center hole of the core body and prevents the core segments from moving inward in the radial direction;
A pair of side plates disposed on both sides of the core body in the axial direction, and holding the core body between the inner side surfaces to prevent movement of each core segment in the axial direction;
In addition, a first dovetail portion comprising one of a dovetail groove or an ant tenon extending in the axial direction is formed on the outer peripheral surface of the core, and extending in the axial direction on the inner peripheral surface of each core segment. A second dovetail portion formed of the other of an ant groove or an ant tenon engaged with the first ant joint portion is formed;
The end plate on one side of the core is fixed to the side plate on one side in the axial direction, and the side plate on the other side in the axial direction is screwed to the inner screw portion provided in the center hole of the core on the inner side surface of the side plate. A rigid core characterized in that it is detachable from the other end of the core by projecting a boss that can be inserted.   The core segment includes a first core segment in which split surfaces at both ends in the circumferential direction are inclined in a direction in which a circumferential width decreases toward a radially inward direction, and the first core segment is a circumferential direction. Are arranged alternately, and the dividing surfaces at both ends in the circumferential direction are inclined inward in the radial direction so as to increase in the circumferential width. The rigid core according to claim 1, wherein the rigid core is movable.   3. The rigid core according to claim 1, wherein the side plates on one side and the other side in the axial direction include support shaft portions that protrude outward in the axial direction.   4. The rigid core according to claim 3, wherein the support shaft portion is formed with a locking portion comprising a key groove or a key-shaped protrusion for preventing rotation on an end surface thereof.

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