JP2018176447A - Bead apex rubber forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rubber from leaking from between the rear shutter wall portion and the outer circumferential surface of each bead core, for the bead cores of various sizes differing in diameter.SOLUTION: Bead core holding means 2 and a forming head 4 are provided. The molding head 4 comprises a molding chamber 11 surrounded by a first side surface S1 and a second side surface S 2 and extending in the circumferential direction on a peripheral surface As of a bead core A, a rubber inflow port 15 opening at the first side surface S1, and a shutter wall portion 9 after closing the molding chamber 11 on the rear side of the rubber inflow port 15. The bead core holding means 2 comprises moving means 24 capable of moving an axial position pi of the held bead core A rearward from the rubber inflow port 11.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a bead apex rubber forming apparatus capable of forming bead apex rubber precisely on the outer peripheral surface of a bead core.

  Patent Document 1 below proposes a bead apex rubber forming device in which a bead apex rubber is integrally formed on the outer peripheral surface of a bead core rotating around an axial center. The apparatus comprises a bead core holding means for holding the bead core rotatably about an axis, and a forming head attached to the rubber extruder. The molding head also has a bead apex rubber molding chamber, a rubber inlet, and a rear shutter wall.

  The forming chamber extends in the circumferential direction on the outer peripheral surface of the bead core surrounded by the inner wall surface on one side in the axial direction and the inner wall surface on the other side. The rubber inlet is formed on an inner wall surface on one side. The rear shutter wall projects from the inner wall surface and closes the molding chamber on the rear side in the rotational direction of the bead core than the rubber inlet.

  On the other hand, in the above apparatus, it is desirable to form bead apex rubber even for bead cores of various sizes with different diameters. However, as shown in FIG. 13, in the above apparatus, the rubber inlet a is formed on the reference line X which vertically rises from the axial center i (not shown) of the bead core A to be held. Therefore, when forming a bead core A having a small diameter, the bottom surface bs of the shutter wall b after that separates from the outer peripheral surface As of the bead core A, and the rubber leaks out from the gap c. The problem is that the molding quality of the The height position of the top portion Ap of the bead core A is regulated by the forming head.

JP, 2013-237224, A

  The present invention can suppress rubber leakage from between the later shutter wall and the outer peripheral surface of the bead core for bead cores of various sizes having different diameters, and can improve the molding quality of bead apex rubber. It is an object to provide a forming apparatus.

The present invention is a bead apex rubber forming device in which bead apex rubber is continuously formed on the outer peripheral surface of a bead core over the entire circumference,
A bead core holding means for holding the bead core rotatably about its axis, and a molding head attached to a rubber extruder;
The forming head is
A forming chamber for forming a bead apex rubber, which is circumferentially extended on the outer peripheral surface of the bead core by being surrounded by the first side surface on one side in the axial direction and the second side surface on the other side;
A rubber inlet opening at the first side;
And a shutter wall after closing the forming chamber on the rotational direction rear side of the bead core with respect to the rubber inlet.
The bead core holding means includes moving means capable of moving the axial center position of the holding bead core to the rear side in the rotational direction with respect to the rubber inlet.

  In the apparatus for forming a bead apex rubber according to the present invention, the moving means moves the axial center position of the bead core within a reference range where the reference line rising perpendicularly from the axial center can intersect the bottom surface of the rear shutter wall. It is preferable to move the

  In the bead apex rubber forming apparatus according to the present invention, the moving means is arranged such that a reference line vertically rising from the axial center passes through the front edge of the bottom of the shutter wall in the rotational direction. Preferably, the axial position is moved.

In the bead apex rubber forming apparatus according to the present invention, the forming head is
A head main body having the first side and provided with a rubber inlet on the first side;
And a cover wall movably supported between the open state in which the second side of the forming chamber is open and the closed state in which the second side is closed to form the forming chamber. Including the body
The covering wall is
A first cover wall provided with the rear shutter wall at the rear end of the second side;
It does not have a rear shutter wall, and when the first cover wall is in an open state, it is formed of a second cover wall that closes only the second side instead of the first cover wall. Is preferred.

  According to the present invention, the bead core holding means comprises moving means capable of moving the axial center position of the held bead core to the rear side in the rotational direction with respect to the rubber inlet. This makes it possible to suppress rubber leakage from between the bottom surface of the later shutter wall and the outer peripheral surface of the bead core to bead cores of various sizes having different diameters, and can improve the quality of the bead apex rubber.

It is the partial side view which expanded the principal part of the bead apex rubber formation apparatus of this invention. It is a perspective view of the principal part of a bead apex rubber formation device. It is sectional drawing along the axial center direction which shows a forming chamber. (A) is sectional drawing seen from the upper direction which shows a shaping | molding chamber, (B) is sectional drawing of the direction orthogonal to an axial center direction. (A), (B) is sectional drawing seen from the upper direction explaining a formation step. (A) is an inlet closing step, (B) is a cross section seen from above explaining the joint space opening step (A) is a joint space closing step, and (B) to (C) are cross sections viewed from the upper side for explaining the connecting step. (A) and (B) are the side view and front view which show an example of the holding means of a cover wall. (A) and (B) are the side view and front view which show the other example of the holding means of a cover wall. (A) and (B) are the side view and front view which show the further another example of the holding means of a cover wall. It is a front view which shows notionally the movement state of the axial center position of the bead core by a bead core holding means. (A), (B) is a front view which shows notionally the reference range which an axial center position moves, and a reference position. It is a front view which shows the problem of the conventional formation apparatus notionally.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIGS. 1 and 2, the bead apex rubber forming apparatus 1 of the present embodiment (sometimes referred to simply as the forming apparatus 1) is a bead core that holds a bead core A for a tire so as to be rotatable about its axis i. A holding means 2 and a molding head 5 attached to the tip of the rubber extruder 4 are provided, and bead apex rubber B is continuously formed on the outer peripheral surface As of the bead core A over the entire circumference.

  The rubber extruder 4 is not particularly limited, and one having a known structure may be appropriately adopted. In this example, one in which a gear pump 4B is connected to the tip of a screw type extruder main body 4A is employed. The rubber extruder 4 can supply the non-vulcanized rubber G to the forming head 5 according to the on / off of the gear pump 4B.

  In the present embodiment, the bead core holding means 2 includes a plurality of (in this example, four) rollers 2a parallel to each other for receiving the inner peripheral surface of the bead core A. Each roller 2 a is rotatably supported by the roller holder 3. Further, each roller 2a is supported so as to be movable radially inward and outward centering on the axial center i via an expansion / contraction diameter means (not shown). Thereby, bead cores A of various sizes with different diameters can be detachably supported. Various known structures can be adopted as the expansion / contraction diameter means. In this example, one of the rollers 2a can be connected to the motor to rotationally drive the held bead core A.

  As shown in FIGS. 2 and 3, a part of the rotating bead core A in the circumferential direction passes through the forming head 5. The molding head 5 is circumferentially surrounded on the outer peripheral surface As of the passing bead core A by the first side surface S1 on one side in the axial center direction of the molding head 5 and the second side surface S2 on the other side. A forming chamber 11 having a triangular cross section is provided.

  Specifically, the molding head 5 includes a head main body 12 fixed to the tip of the rubber extruder 4 and a cover wall 14 supported by the head main body 12 via holding means 13. The head main body 12 forms the first side surface S1 by the outward surface so. A rubber inflow port 15 is formed on the first side surface S1 to allow the unvulcanized rubber G from the rubber extruder 4 to flow into the molding chamber 11.

  In the present embodiment, the cover wall 14 is formed of a first cover wall 14A and a second cover wall 14B, as shown in FIGS. 8 (A) and 8 (B).

  As shown in FIGS. 3 and 4A, the first cover wall body 14A is on the rear side of the second side surface S2 constituting the molding chamber 11 and the rubber inflow port 15 (the rear side of the bead core A in the rotational direction And the shutter wall 9 after the molding chamber 11 is closed. In this example, the rear shutter wall 9 is disposed at the rear end (rear end in the rotational direction F) of the second side surface S2. The rear shutter wall 9 is preferably disposed close to the rubber inlet 15, and the circumferential distance L between the rear shutter wall 9 and the rubber inlet 15 (FIG. 4B) 1 mm or less is preferable.

  As shown in FIG. 3, in this example, the first cover wall 14A is in the form of a block, and the inward surface si is continuous with the inclined surface portion si1 inclined downward and the upper edge of the inclined surface portion si1. An upper contact surface portion si2 capable of coming into contact with the outwardly facing surface so, and an abutment surface portion si3 connected to the rear edge of the inclined surface portion si1 and capable of coming into contact with the outwardly facing surface so. Then, the inclined surface portion si1 forms the second side surface S2. The upper contact surface portion si2 closes the upper side of the molding chamber 11 and functions as a stopper for the first cover wall 14A in the closed state Y2. Further, the contact surface portion si3 on the side forms the rear shutter wall 9.

  As shown in FIGS. 8A and 8B, the first cover wall body 14A is in an open state Y1 in which the second side S2 side of the molding chamber 11 is opened through the first holding means 13A, and The two side surfaces S2 side is movably supported between a closed state Y2 which is closed to form the molding chamber 11.

  In this example, the first holding means 13A tilts up and down around the fulcrum Q1 at which the arm 16 is fixed to the first cover wall 14A at one end and the arm 16 is provided on the head main body 12 And a case is provided. The arm 16 is not particularly limited, but in the present example, it has, for example, an L-shaped main portion 16A fixed at one end to the first cover wall 14A and pivoted at the other end by the fulcrum Q1. The driving tool 17 is a cylinder in this example, and is pivotally supported by the head main body 12 so as to be capable of tilting up and down around the fulcrum Q2, and the rod tip thereof has the main part 16A, for example, the sub part 16B. It is pivotally supported at a position Q3 different from the fulcrum Q1. The first cover wall 14A can be moved between the open state Y1 and the closed state Y2 by extension and contraction of the rod.

  In addition, as shown in FIG. 7, the second cover wall 14B does not have the rear shutter wall 9 and when the first cover wall 14A is in the open state Y1, the second cover wall 14A is mounted on the first cover wall 14A. Instead, only the second side of the forming chamber 11 is closed.

The second cover wall 14B has substantially the same configuration as the first cover wall 14A, and differs in the following points.
a) The second cover wall 14 B does not have the rear shutter wall 9.
b) The second side S2 of the second cover wall 14B is further rearward than the second side S2 of the first cover wall 14A beyond the rear shutter wall 9 (rear side in the rotational direction F) It has an extending surface portion 18 which extends. In the present invention, in order to distinguish from the second side surface S2 of the first cover wall 14A, the second side surface S2 of the second cover wall 14B may be referred to as a third side surface S3. As described above, since the third side surface S3 has the extension surface portion 18, it is possible to bridge between the rear end portion Br and the front end portion Bf of the bead apex rubber B in the joint space closing step P4 described later. It will be possible to close

  As shown in FIGS. 8A and 8B, the second cover wall 14B is also movably supported between the open state Y1 and the closed state Y2 via the second holding means 13B. . When the first cover wall 14A is in the closed state Y2, the second cover wall 14B waits in the open state Y1. When the first cover wall 14A is in the open state Y1, the second cover wall 14B is in the closed state Y2, and only the second side of the forming chamber 11 is closed instead of the first cover wall 14A. . That is, the joint space J is closed.

  The second holding means 13B has the same configuration as the first holding means 13A, and can alternately open and close the second side of the molding chamber 11 by changing the direction of tilting.

  As shown in FIGS. 4A and 4B, the head body 12 of the present example includes a shutter 30 extending from the front side to the rear side along the first side surface S1. The shutter 30 can open and close the rubber inflow port 15 by sliding forward and backward on the front side of the rear shutter wall 9.

  Specifically, a guide groove 31 for guiding the shutter 30 is recessed in the first side surface S1. The rear end 31E of the guide groove 31 terminates on the front side relative to the position of the rear shutter wall 9. The rubber inlet 15 opens at the bottom of the guide groove 31. The shutter 30 has a plate-like shape, and is slidably held in the guide groove 31 back and forth. The surface of the shutter 30 and the first side surface S1 are substantially flush with each other. The shutter 30 is operated by the moving means 32. In this example, the moving means 32 is a cylinder 32A supported on the side surface of the head body 12 via the mounting plate 33, and the front end of the shutter 30 is attached to the rod end thereof.

  FIGS. 9A and 9B show another example of the forming head 5. In this embodiment, a movable table 20 movable in the circumferential direction is provided on the head main body 12, and the first and second holding means 13A and 13B are attached side by side on the movable table 20. Therefore, the first and second holding means 13A, 13B can alternately open and close the second side face of the forming chamber 11 by the movement of the movable table 20 in the circumferential direction while making the tilt directions the same.

  10A and 10B show other examples of the first and second holding means 13A and 13B. In this example, the first and second holding means 13A and 13B do not have the arm 16 pivotably supported by the first and second holding means 13A and 13B, respectively. It is supported slidably along the outward facing surface so. Specifically, the first and second holding means 13A and 13B each include, for example, a cylinder 23 fixed to the head body 12 via, for example, a mounting bracket 22, and the lower end of the rod of each cylinder 23 1, the second cover wall body 14A, 14B is provided slidably along the outward facing surface so. In the present embodiment, a cylinder with a guide is employed as the cylinder 23, but guides (not shown) for guiding the first and second cover wall bodies 14A and 14B can be provided on the head body 12 as appropriate.

  Further, in the present invention, as schematically shown in FIG. 11, the bead core holding means 2 sets the axial center position pi of the held bead core A to the rear side (rear side in the rotational direction F) than the rubber inlet 15. A movable moving means 24 (shown in FIG. 1) is provided.

  As shown in FIG. 1, the moving means 24 of this example supports the roller holding base 3 so as to be movable in the vertical direction, and the horizontal movement base 25 which supports the roller holding base 3 so as to be movable in the horizontal direction. A lifting platform 26 is provided. In the present example, it is shown that the lift 26 is guided via a rail attached to the frame 27 and the lateral carriage 25 is guided via a rail attached to the lift 26. The lateral moving table 25 and the lifting table 26 are driven by a known driving means using, for example, a ball screw mechanism. Thereby, the bead core holding means 2 of this example can move the axial center i laterally and vertically.

  The moving means 24 is, as shown in an exaggerated manner in FIG. 12A, an axis within a reference range y where the reference line X, which rises perpendicularly from the axial center i, can intersect with the bottom surface 9s of the shutter wall 9 later. Move the heart position pi. In particular, as shown in FIG. 12B, it is preferable to move the axial center position pi to a reference position py that passes through the rotation direction front edge Ef of the bottom surface 9s within the reference range y.

  Thus, by moving the axial center position pi laterally to the reference range y, in particular to the reference position py, the outer peripheral surface As of the bead core A with respect to the bead cores A of various sizes having different diameters The bottom surface 9s of the portion 9 can be in contact with or in proximity to the bottom surface 9s, and the leakage of the unvulcanized rubber G from between the outer peripheral surface As and the bottom surface 9s can be suppressed.

  The bead core holding means 2 having the moving means 24 can also be employed in a forming apparatus 1 as described in Patent Document 1. Specifically, the rear shutter wall 9 is provided in the head main body 12 so as to be able to protrude and retract in the axial direction from the first side surface S1, and the cover wall 14 is configured only by the second cover wall 14B. Ru. Also in such a forming apparatus 1, similar effects, that is, leakage of unvulcanized rubber G from between the outer peripheral surface As and the bottom surface 9s can be suppressed with respect to bead cores A of various sizes having different diameters.

  In addition, various structures other than this example can be suitably adopted as the moving means 24.

  Next, a method of forming a bead apex rubber (which may be simply referred to as a forming method) using the forming apparatus 1 of this example will be described.

  This forming method is, as schematically shown in FIG. 2, a forming process in which the bead apex rubber B is integrally formed on the outer peripheral surface As of the rotating bead core A by flowing the unvulcanized rubber G into the molding chamber 11. Provide

  The forming process includes a forming step P1, an inlet closing step P2, a joint space opening step P3, a joint space closing step P4, and a connection step P5.

  5 to 7 are cross-sectional views of the molding chamber 11 as viewed from above, and for the sake of convenience, the bead core A is drawn by an alternate long and short dash line. As shown in FIG. 5A, in the forming step P1, using the first cover wall 14A, the front side of the forming chamber 11 is open and the rear side is closed by the rear shutter wall 9; It is performed in the rear closed state R (closed state Y2). In the rear closed state R, the unvulcanized rubber G is allowed to flow in from the rubber inlet 15 while rotating the bead core A. Thereby, the bead apex rubber B having the tip end portion Bf is gradually formed.

  Next, in the inlet closing step P2, as shown in FIG. 5 (B), when the bead core A makes a round and the tip end portion Bf approaches the later shutter wall portion 9, the bead core A by the bead core holding means 2 Stop the rotation of.

  In synchronization with this rotation stop, the gear pump 4B is temporarily stopped. However, even after the stop, the rubber leaks from the rubber inflow port 15 due to the internal pressure of the rubber flow path. Therefore, as shown in FIG. 6A, the shutter 30 closes the rubber inlet 15 to prevent the rubber from leaking from the rubber inlet 15. In addition, since the shutter 30 slides on the front side of the later shutter wall 9, it does not interfere with the later shutter wall 9, and smooth opening and closing operations can be performed.

  Next, in the joint space opening step P3, as shown in FIG. 6B, in the closed state of the rubber inflow port 15 by the shutter 30, the first cover wall body 14A is brought into the open state Y1. That is, the second side surface S2 is removed together with the rear shutter wall 9. As a result, between the rear end portion Br and the front end portion Bf of the bead apex rubber B, a joint space J in which the second side surface S2 side is open is formed.

  Next, in the joint space closing step P4, as shown in FIG. 7A, the forming chamber 11 is brought into the closed state Y2 using the second cover wall 14B instead of the first cover wall 14A. That is, instead of the second side surface S2 of the first cover wall body 14A, the third side surface S3 of the second cover wall body 14B straddling at least the rear end Br and the front end Bf is disposed. Space J is closed.

  Next, in the connection step P5, the gear pump 4B is operated, and as shown in FIGS. 7 (B) and 7 (C), the shutter 30 opens the rubber inlet 15 so that the joint space J is closed. The vulcanized rubber G is made to flow. The rear end Br and the front end Bf are integrally connected by the inflowing rubber. Here, since the rubber inflow port 15 is in proximity to the rear shutter wall 9, the unvulcanized rubber G from the rubber inflow port 15 can easily flow into the joint space J.

  After the connection step P5, after stopping the gear pump 4B and closing the rubber inlet 15 by the shutter 30, the second cover wall 14B is in the open state Y1, and the core assembly is taken out.

  As mentioned above, although the especially preferable embodiment of this invention was explained in full detail, this invention can be deform | transformed into a various aspect, and can be implemented, without being limited to embodiment of illustration.

DESCRIPTION OF SYMBOLS 1 bead apex rubber forming apparatus 2 bead core holding means 4 rubber extruder 5 shutter wall part 9s after molding head 9 bottom face 11 molding chamber 12 head main body 14 cover wall body 14A first cover wall body 14B second cover wall body 15 Rubber inlet 24 Moving means A Bead core As Outer peripheral surface B Bead apex rubber i Axial center pi Axial center position py Reference position S1 First side S2 Second side X Reference line y Reference range Y1 Open state Y2 Closed state

Claims (4)

A bead apex rubber forming apparatus in which bead apex rubber is continuously formed on the outer peripheral surface of the bead core over the entire circumference,
A bead core holding means for holding the bead core rotatably about its axis, and a molding head attached to a rubber extruder;
The forming head is
A forming chamber for forming a bead apex rubber, which is circumferentially extended on the outer peripheral surface of the bead core by being surrounded by the first side surface on one side in the axial direction and the second side surface on the other side;
A rubber inlet opening at the first side;
And a shutter wall after closing the forming chamber on the rotational direction rear side of the bead core with respect to the rubber inlet.
The bead apex rubber forming apparatus, wherein the bead core holding means comprises moving means capable of moving the axial center position of the held bead core to the rear side in the rotational direction with respect to the rubber inlet.   The bead apex rubber formation according to claim 1, wherein the moving means moves the axial center position of the bead core to a reference range in which a reference line vertically rising from the axial center can intersect the bottom surface of the rear shutter wall. apparatus.   The axial movement of the bead core according to claim 1 or 2, wherein the moving means moves the axial position of the bead core to a reference position where a reference line vertically rising from the axial center passes through the rotational direction front edge of the bottom of the rear shutter wall. Bead apex rubber forming equipment. The forming head is
A head main body having the first side and provided with a rubber inlet on the first side;
And a cover wall movably supported between the open state in which the second side of the forming chamber is open and the closed state in which the second side is closed to form the forming chamber. Including the body
The covering wall is
A first cover wall provided with the rear shutter wall at the rear end of the second side;
It does not have a rear shutter wall, and when the first cover wall is in an open state, it is formed of a second cover wall that closes only the second side instead of the first cover wall. The bead apex rubber forming apparatus according to any one of claims 1 to 3.

Images